diff --git a/Cargo.toml b/Cargo.toml
index 087a8463..42753f52 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "async-graphql"
-version = "1.5.1"
+version = "1.5.2"
 authors = ["sunli <scott_s829@163.com>"]
 edition = "2018"
 description = "The GraphQL server library implemented by rust"
@@ -18,7 +18,7 @@ default = ["bson", "chrono", "uuid", "url", "validators"]
 validators = ["regex", "once_cell"]
 
 [dependencies]
-async-graphql-derive = { path = "async-graphql-derive", version = "1.5.1" }
+async-graphql-derive = { path = "async-graphql-derive", version = "1.5.2" }
 graphql-parser = "0.2.3"
 anyhow = "1.0.26"
 thiserror = "1.0.11"
diff --git a/README.md b/README.md
index 2ab06905..8a7aec64 100644
--- a/README.md
+++ b/README.md
@@ -96,7 +96,9 @@ Open `http://localhost:8000` in browser
             - [X] FIELD
             - [X] FRAGMENT_SPREAD
             - [X] INLINE_FRAGMENT
-    - [X] Schema
+    - [X] Introspection
+        - [X] Query
+        - [X] Disable introspection
     - [X] Multipart Request (https://github.com/jaydenseric/graphql-multipart-request-spec)
         - [X] Actix-web
     - [X] Cursor Connections
@@ -118,6 +120,8 @@ Open `http://localhost:8000` in browser
         - [X] List
             - [X] ListMaxLength
             - [X] ListMinLength
+    - [ ] Limit query complexity
+    - [ ] Limit query depth 
 - [X] Subscription
     - [X] Filter
     - [X] WebSocket transport
diff --git a/async-graphql-actix-web/Cargo.toml b/async-graphql-actix-web/Cargo.toml
index ec37824b..10821cb0 100644
--- a/async-graphql-actix-web/Cargo.toml
+++ b/async-graphql-actix-web/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "async-graphql-actix-web"
-version = "0.6.1"
+version = "0.6.2"
 authors = ["sunli <scott_s829@163.com>"]
 edition = "2018"
 description = "async-graphql for actix-web"
@@ -13,7 +13,7 @@ keywords = ["futures", "async", "graphql"]
 categories = ["network-programming", "asynchronous"]
 
 [dependencies]
-async-graphql = { path = "..", version = "1.5.1" }
+async-graphql = { path = "..", version = "1.5.2" }
 actix-web = "2.0.0"
 actix-multipart = "0.2.0"
 actix-web-actors = "2.0.0"
diff --git a/async-graphql-derive/Cargo.toml b/async-graphql-derive/Cargo.toml
index 97c18c3f..712e3ee6 100644
--- a/async-graphql-derive/Cargo.toml
+++ b/async-graphql-derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "async-graphql-derive"
-version = "1.5.1"
+version = "1.5.2"
 authors = ["sunli <scott_s829@163.com>"]
 edition = "2018"
 description = "Macros for async-graphql"
diff --git a/src/error.rs b/src/error.rs
index 1d6561d8..27f4d557 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -148,6 +148,12 @@ pub enum QueryError {
         /// Actual type
         actual: String,
     },
+
+    #[error("Too complex.")]
+    TooComplex,
+
+    #[error("Too deep.")]
+    TooDeep,
 }
 
 /// Creates a wrapper with an error location
diff --git a/src/query.rs b/src/query.rs
index 0c94dd2c..a2e23da2 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -1,8 +1,8 @@
 use crate::context::Data;
 use crate::registry::{CacheControl, Registry};
 use crate::types::QueryRoot;
-use crate::validation::check_rules;
-use crate::{ContextBase, OutputValueType, Result};
+use crate::validation::{check_rules, CheckResult};
+use crate::{ContextBase, OutputValueType, Result, Schema};
 use crate::{ObjectType, QueryError, QueryParseError, Variables};
 use bytes::Bytes;
 use graphql_parser::parse_query;
@@ -17,17 +17,15 @@ enum Root<'a, Query, Mutation> {
 }
 
 /// Query builder
-pub struct QueryBuilder<'a, Query, Mutation> {
-    pub(crate) query: &'a QueryRoot<Query>,
-    pub(crate) mutation: &'a Mutation,
-    pub(crate) registry: &'a Registry,
+pub struct QueryBuilder<'a, Query, Mutation, Subscription> {
+    pub(crate) schema: &'a Schema<Query, Mutation, Subscription>,
     pub(crate) source: &'a str,
     pub(crate) operation_name: Option<&'a str>,
     pub(crate) variables: Option<Variables>,
     pub(crate) data: &'a Data,
 }
 
-impl<'a, Query, Mutation> QueryBuilder<'a, Query, Mutation> {
+impl<'a, Query, Mutation, Subscription> QueryBuilder<'a, Query, Mutation, Subscription> {
     /// Specify the operation name.
     pub fn operator_name(self, name: &'a str) -> Self {
         QueryBuilder {
@@ -47,7 +45,23 @@ impl<'a, Query, Mutation> QueryBuilder<'a, Query, Mutation> {
     /// Prepare query
     pub fn prepare(self) -> Result<PreparedQuery<'a, Query, Mutation>> {
         let document = parse_query(self.source).map_err(|err| QueryParseError(err.to_string()))?;
-        let cache_control = check_rules(self.registry, &document)?;
+        let CheckResult {
+            cache_control,
+            complexity,
+            depth,
+        } = check_rules(&self.schema.registry, &document)?;
+
+        if let Some(limit_complexity) = self.schema.complexity {
+            if complexity > limit_complexity {
+                return Err(QueryError::TooComplex.into());
+            }
+        }
+
+        if let Some(limit_depth) = self.schema.depth {
+            if depth > limit_depth {
+                return Err(QueryError::TooDeep.into());
+            }
+        }
 
         let mut fragments = HashMap::new();
         let mut selection_set = None;
@@ -59,14 +73,14 @@ impl<'a, Query, Mutation> QueryBuilder<'a, Query, Mutation> {
                 Definition::Operation(operation_definition) => match operation_definition {
                     OperationDefinition::SelectionSet(s) => {
                         selection_set = Some(s);
-                        root = Some(Root::Query(self.query));
+                        root = Some(Root::Query(&self.schema.query));
                     }
                     OperationDefinition::Query(query)
                         if query.name.is_none() || query.name.as_deref() == self.operation_name =>
                     {
                         selection_set = Some(query.selection_set);
                         variable_definitions = Some(query.variable_definitions);
-                        root = Some(Root::Query(self.query));
+                        root = Some(Root::Query(&self.schema.query));
                     }
                     OperationDefinition::Mutation(mutation)
                         if mutation.name.is_none()
@@ -74,7 +88,7 @@ impl<'a, Query, Mutation> QueryBuilder<'a, Query, Mutation> {
                     {
                         selection_set = Some(mutation.selection_set);
                         variable_definitions = Some(mutation.variable_definitions);
-                        root = Some(Root::Mutation(self.mutation));
+                        root = Some(Root::Mutation(&self.schema.mutation));
                     }
                     OperationDefinition::Subscription(subscription)
                         if subscription.name.is_none()
@@ -91,7 +105,7 @@ impl<'a, Query, Mutation> QueryBuilder<'a, Query, Mutation> {
         }
 
         Ok(PreparedQuery {
-            registry: self.registry,
+            registry: &self.schema.registry,
             variables: self.variables.unwrap_or_default(),
             data: self.data,
             fragments,
diff --git a/src/schema.rs b/src/schema.rs
index 495188d1..8089aec7 100644
--- a/src/schema.rs
+++ b/src/schema.rs
@@ -9,11 +9,13 @@ use std::collections::HashMap;
 
 /// GraphQL schema
 pub struct Schema<Query, Mutation, Subscription> {
-    query: QueryRoot<Query>,
-    mutation: Mutation,
+    pub(crate) query: QueryRoot<Query>,
+    pub(crate) mutation: Mutation,
     pub(crate) subscription: Subscription,
     pub(crate) registry: Registry,
     pub(crate) data: Data,
+    pub(crate) complexity: Option<usize>,
+    pub(crate) depth: Option<usize>,
 }
 
 impl<Query: ObjectType, Mutation: ObjectType, Subscription: SubscriptionType>
@@ -99,14 +101,37 @@ impl<Query: ObjectType, Mutation: ObjectType, Subscription: SubscriptionType>
         }
 
         Self {
-            query: QueryRoot { inner: query },
+            query: QueryRoot {
+                inner: query,
+                disable_introspection: false,
+            },
             mutation,
             subscription,
             registry,
             data: Default::default(),
+            complexity: None,
+            depth: None,
         }
     }
 
+    /// Disable introspection query
+    pub fn disable_introspection(mut self) -> Self {
+        self.query.disable_introspection = true;
+        self
+    }
+
+    /// Set limit complexity, Default no limit.
+    pub fn limit_complexity(mut self, complexity: usize) -> Self {
+        self.complexity = Some(complexity);
+        self
+    }
+
+    /// Set limit complexity, Default no limit.
+    pub fn limit_depth(mut self, depth: usize) -> Self {
+        self.depth = Some(depth);
+        self
+    }
+
     /// Add a global data that can be accessed in the `Context`.
     pub fn data<D: Any + Send + Sync>(mut self, data: D) -> Self {
         self.data.insert(data);
@@ -114,11 +139,9 @@ impl<Query: ObjectType, Mutation: ObjectType, Subscription: SubscriptionType>
     }
 
     /// Start a query and return `QueryBuilder`.
-    pub fn query<'a>(&'a self, source: &'a str) -> QueryBuilder<'a, Query, Mutation> {
+    pub fn query<'a>(&'a self, source: &'a str) -> QueryBuilder<'a, Query, Mutation, Subscription> {
         QueryBuilder {
-            query: &self.query,
-            mutation: &self.mutation,
-            registry: &self.registry,
+            schema: self,
             source,
             operation_name: None,
             variables: None,
diff --git a/src/types/query_root.rs b/src/types/query_root.rs
index beb30f90..1c27a27e 100644
--- a/src/types/query_root.rs
+++ b/src/types/query_root.rs
@@ -1,7 +1,7 @@
 use crate::model::{__Schema, __Type};
 use crate::{
     do_resolve, registry, Context, ContextSelectionSet, ErrorWithPosition, ObjectType,
-    OutputValueType, Result, Type, Value,
+    OutputValueType, QueryError, Result, Type, Value,
 };
 use graphql_parser::query::Field;
 use std::borrow::Cow;
@@ -9,6 +9,7 @@ use std::collections::HashMap;
 
 pub struct QueryRoot<T> {
     pub inner: T,
+    pub disable_introspection: bool,
 }
 
 impl<T: Type> Type for QueryRoot<T> {
@@ -67,6 +68,14 @@ impl<T: Type> Type for QueryRoot<T> {
 impl<T: ObjectType + Send + Sync> ObjectType for QueryRoot<T> {
     async fn resolve_field(&self, ctx: &Context<'_>, field: &Field) -> Result<serde_json::Value> {
         if field.name.as_str() == "__schema" {
+            if self.disable_introspection {
+                return Err(QueryError::FieldNotFound {
+                    field_name: field.name.clone(),
+                    object: Self::type_name().to_string(),
+                }
+                .into());
+            }
+
             let ctx_obj = ctx.with_item(&field.selection_set);
             return OutputValueType::resolve(
                 &__Schema {
diff --git a/src/validation/mod.rs b/src/validation/mod.rs
index 115bb9e5..3ff52e00 100644
--- a/src/validation/mod.rs
+++ b/src/validation/mod.rs
@@ -1,6 +1,7 @@
 mod rules;
 mod utils;
 mod visitor;
+mod visitors;
 
 use crate::error::RuleErrors;
 use crate::registry::Registry;
@@ -8,9 +9,18 @@ use crate::{CacheControl, Result};
 use graphql_parser::query::Document;
 use visitor::{visit, VisitorContext, VisitorNil};
 
-pub fn check_rules(registry: &Registry, doc: &Document) -> Result<CacheControl> {
+pub struct CheckResult {
+    pub cache_control: CacheControl,
+    pub complexity: usize,
+    pub depth: usize,
+}
+
+pub fn check_rules(registry: &Registry, doc: &Document) -> Result<CheckResult> {
     let mut ctx = VisitorContext::new(registry, doc);
     let mut cache_control = CacheControl::default();
+    let mut complexity = 0;
+    let mut depth = 0;
+
     let mut visitor = VisitorNil
         .with(rules::ArgumentsOfCorrectType::default())
         .with(rules::DefaultValuesOfCorrectType)
@@ -37,14 +47,21 @@ pub fn check_rules(registry: &Registry, doc: &Document) -> Result<CacheControl>
         .with(rules::KnownDirectives::default())
         .with(rules::OverlappingFieldsCanBeMerged)
         .with(rules::UploadFile)
-        .with(rules::CacheControlCalculate {
+        .with(visitors::CacheControlCalculate {
             cache_control: &mut cache_control,
-        });
+        })
+        .with(visitors::ComplexityCalculate {
+            complexity: &mut complexity,
+        })
+        .with(visitors::DepthCalculate::new(&mut depth));
 
     visit(&mut visitor, &mut ctx, doc);
     if !ctx.errors.is_empty() {
-        Err(RuleErrors { errors: ctx.errors }.into())
-    } else {
-        Ok(cache_control)
+        return Err(RuleErrors { errors: ctx.errors }.into());
     }
+    Ok(CheckResult {
+        cache_control,
+        complexity,
+        depth: depth as usize,
+    })
 }
diff --git a/src/validation/rules/mod.rs b/src/validation/rules/mod.rs
index 386b63c8..a54c00ba 100644
--- a/src/validation/rules/mod.rs
+++ b/src/validation/rules/mod.rs
@@ -1,5 +1,4 @@
 mod arguments_of_correct_type;
-mod cache_control;
 mod default_values_of_correct_type;
 mod fields_on_correct_type;
 mod fragments_on_composite_types;
@@ -26,7 +25,6 @@ mod variables_are_input_types;
 mod variables_in_allowed_position;
 
 pub use arguments_of_correct_type::ArgumentsOfCorrectType;
-pub use cache_control::CacheControlCalculate;
 pub use default_values_of_correct_type::DefaultValuesOfCorrectType;
 pub use fields_on_correct_type::FieldsOnCorrectType;
 pub use fragments_on_composite_types::FragmentsOnCompositeTypes;
diff --git a/src/validation/visitor.rs b/src/validation/visitor.rs
index 2bed7694..20ec26ad 100644
--- a/src/validation/visitor.rs
+++ b/src/validation/visitor.rs
@@ -463,11 +463,13 @@ fn visit_selection_set<'a, V: Visitor<'a>>(
     ctx: &mut VisitorContext<'a>,
     selection_set: &'a SelectionSet,
 ) {
-    v.enter_selection_set(ctx, selection_set);
-    for selection in &selection_set.items {
-        visit_selection(v, ctx, selection);
+    if !selection_set.items.is_empty() {
+        v.enter_selection_set(ctx, selection_set);
+        for selection in &selection_set.items {
+            visit_selection(v, ctx, selection);
+        }
+        v.exit_selection_set(ctx, selection_set);
     }
-    v.exit_selection_set(ctx, selection_set);
 }
 
 fn visit_selection<'a, V: Visitor<'a>>(
@@ -578,6 +580,9 @@ fn visit_fragment_spread<'a, V: Visitor<'a>>(
 ) {
     v.enter_fragment_spread(ctx, fragment_spread);
     visit_directives(v, ctx, &fragment_spread.directives);
+    if let Some(fragment) = ctx.fragment(fragment_spread.fragment_name.as_str()) {
+        visit_selection_set(v, ctx, &fragment.selection_set);
+    }
     v.exit_fragment_spread(ctx, fragment_spread);
 }
 
diff --git a/src/validation/rules/cache_control.rs b/src/validation/visitors/cache_control.rs
similarity index 100%
rename from src/validation/rules/cache_control.rs
rename to src/validation/visitors/cache_control.rs
diff --git a/src/validation/visitors/complexity.rs b/src/validation/visitors/complexity.rs
new file mode 100644
index 00000000..3508c22f
--- /dev/null
+++ b/src/validation/visitors/complexity.rs
@@ -0,0 +1,12 @@
+use crate::validation::visitor::{Visitor, VisitorContext};
+use graphql_parser::query::Field;
+
+pub struct ComplexityCalculate<'a> {
+    pub complexity: &'a mut usize,
+}
+
+impl<'ctx, 'a> Visitor<'ctx> for ComplexityCalculate<'a> {
+    fn enter_field(&mut self, _ctx: &mut VisitorContext<'_>, _field: &Field) {
+        *self.complexity += 1;
+    }
+}
diff --git a/src/validation/visitors/depth.rs b/src/validation/visitors/depth.rs
new file mode 100644
index 00000000..9f9c06ba
--- /dev/null
+++ b/src/validation/visitors/depth.rs
@@ -0,0 +1,68 @@
+use crate::validation::visitor::{Visitor, VisitorContext};
+use graphql_parser::query::{FragmentSpread, InlineFragment, SelectionSet};
+
+pub struct DepthCalculate<'a> {
+    max_depth: &'a mut i32,
+    current_depth: i32,
+}
+
+impl<'a> DepthCalculate<'a> {
+    pub fn new(max_depth: &'a mut i32) -> Self {
+        *max_depth = -1;
+        Self {
+            max_depth,
+            current_depth: -1,
+        }
+    }
+}
+
+impl<'ctx, 'a> Visitor<'ctx> for DepthCalculate<'a> {
+    fn enter_selection_set(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _selection_set: &'ctx SelectionSet,
+    ) {
+        self.current_depth += 1;
+        *self.max_depth = (*self.max_depth).max(self.current_depth);
+    }
+
+    fn exit_selection_set(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _selection_set: &'ctx SelectionSet,
+    ) {
+        self.current_depth -= 1;
+    }
+
+    fn enter_fragment_spread(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _fragment_spread: &'ctx FragmentSpread,
+    ) {
+        self.current_depth -= 1;
+    }
+
+    fn exit_fragment_spread(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _fragment_spread: &'ctx FragmentSpread,
+    ) {
+        self.current_depth += 1;
+    }
+
+    fn enter_inline_fragment(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _inline_fragment: &'ctx InlineFragment,
+    ) {
+        self.current_depth -= 1;
+    }
+
+    fn exit_inline_fragment(
+        &mut self,
+        _ctx: &mut VisitorContext<'ctx>,
+        _inline_fragment: &'ctx InlineFragment,
+    ) {
+        self.current_depth += 1;
+    }
+}
diff --git a/src/validation/visitors/mod.rs b/src/validation/visitors/mod.rs
new file mode 100644
index 00000000..03765d98
--- /dev/null
+++ b/src/validation/visitors/mod.rs
@@ -0,0 +1,7 @@
+mod cache_control;
+mod complexity;
+mod depth;
+
+pub use cache_control::CacheControlCalculate;
+pub use complexity::ComplexityCalculate;
+pub use depth::DepthCalculate;