diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..4ed3609
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,58 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+- **Group SetNotFoundHandle** - Support custom 404 handler for router groups (#229)
+  - Added `SetNotFoundHandle(handler StandardHandle)` method to Group interface
+  - Group-level 404 handler takes priority over app-level handler
+  - Example: `apiGroup.SetNotFoundHandle(func(ctx Context) error { ... })`
+
+- **Trailing Slash Redirect Configuration** - Control trailing slash redirect behavior (#245)
+  - Added `EnabledRedirectTrailingSlash` configuration option
+  - Default is `false` to match net/http behavior
+  - Set to `true` to enable automatic 301 redirect for trailing slashes
+
+- **CORS Preflight Support** - Fixed CORS preflight request handling (#250)
+  - Modified `DefaultAutoOPTIONSHandler` to include CORS headers
+  - Better integration with CORS middleware
+
+### Fixed
+- **Security Vulnerabilities** - Upgraded dependencies to fix security issues
+  - Upgraded `gopkg.in/yaml.v2` to `v3.0.1` (fixes DoS vulnerability)
+  - Upgraded `golang.org/x/net` to `v0.33.0` (fixes XSS and proxy bypass)
+
+### Changed
+- **Go Version** - Maintained Go 1.21 compatibility
+- **Code Quality** - Improved error handling and nil checks
+
+## [1.0.0] - Previous Release
+
+### Features
+- Support for go mod
+- Static routing, parameter routing, group routing
+- Route support for file/directory services
+- HttpModule support
+- Middleware support (App, Group, Router levels)
+- STRING/JSON/JSONP/HTML output formats
+- Built-in Mock capability
+- Custom Context support
+- Timeout Hook integration
+- Global HTTP error handling
+- Global logging
+- Hijack and WebSocket support
+- Built-in Cache support
+- Built-in Session support with Redis failover
+- Built-in TLS support
+- Third-party template engine support
+- Modular configuration
+- Built-in statistics
+
+---
+
+For more details, see [GitHub Releases](https://github.com/devfeel/dotweb/releases).
diff --git a/README.md b/README.md
index 50423a5..0846f32 100644
--- a/README.md
+++ b/README.md
@@ -175,6 +175,28 @@ test：
 <br>curl http://127.0.0.1/user
 <br>curl http://127.0.0.1/user/profile
 
+#### 5) group SetNotFoundHandle (Since v1.8)
+支持为路由组设置独立的 404 处理器，优先于应用级别的 NotFoundHandler。
+``` go
+    // Create API group
+    apiGroup := server.Group("/api")
+    
+    // Set group-level 404 handler
+    apiGroup.SetNotFoundHandle(func(ctx dotweb.Context) error {
+        ctx.Response().Header().Set("Content-Type", "application/json")
+        return ctx.WriteString(`{"code": 404, "message": "API resource not found"}`)
+    })
+    
+    // Register routes
+    apiGroup.GET("/users", func(ctx dotweb.Context) error {
+        return ctx.WriteString("Users list")
+    })
+```
+Behavior:
+<br>Request to `/api/users` → Returns "Users list"
+<br>Request to `/api/unknown` → Returns JSON 404 response (group handler)
+<br>Request to `/unknown` → Returns global 404 (app handler)
+
 
 ## 6. Binder
 * HttpContext.Bind(interface{})
diff --git a/group.go b/group.go
index 2e8f516..e144445 100644
--- a/group.go
+++ b/group.go
@@ -2,27 +2,59 @@ package dotweb
 
 import "reflect"
 
-type (
-	Group interface {
-		Use(m ...Middleware) Group
-		Group(prefix string, m ...Middleware) Group
-		DELETE(path string, h HttpHandle) RouterNode
-		GET(path string, h HttpHandle) RouterNode
-		HEAD(path string, h HttpHandle) RouterNode
-		OPTIONS(path string, h HttpHandle) RouterNode
-		PATCH(path string, h HttpHandle) RouterNode
-		POST(path string, h HttpHandle) RouterNode
-		PUT(path string, h HttpHandle) RouterNode
-		ServerFile(path string, fileroot string) RouterNode
-		RegisterRoute(method, path string, h HttpHandle) RouterNode
-	}
-	xGroup struct {
-		prefix           string
-		middlewares      []Middleware
-		allRouterExpress map[string]struct{}
-		server           *HttpServer
-	}
-)
+// Group is the interface that wraps the group router methods.
+// A Group allows you to create routes with a common prefix and middleware chain.
+type Group interface {
+	// Use registers middleware(s) to the group.
+	// Middleware is applied to all routes in this group.
+	Use(m ...Middleware) Group
+	
+	// Group creates a new sub-group with the given prefix and optional middleware.
+	// The sub-group inherits middleware from the parent group.
+	Group(prefix string, m ...Middleware) Group
+	
+	// DELETE registers a new DELETE route with the given path and handler.
+	DELETE(path string, h HttpHandle) RouterNode
+	
+	// GET registers a new GET route with the given path and handler.
+	GET(path string, h HttpHandle) RouterNode
+	
+	// HEAD registers a new HEAD route with the given path and handler.
+	HEAD(path string, h HttpHandle) RouterNode
+	
+	// OPTIONS registers a new OPTIONS route with the given path and handler.
+	OPTIONS(path string, h HttpHandle) RouterNode
+	
+	// PATCH registers a new PATCH route with the given path and handler.
+	PATCH(path string, h HttpHandle) RouterNode
+	
+	// POST registers a new POST route with the given path and handler.
+	POST(path string, h HttpHandle) RouterNode
+	
+	// PUT registers a new PUT route with the given path and handler.
+	PUT(path string, h HttpHandle) RouterNode
+	
+	// ServerFile registers a file server route with the given path and file root.
+	ServerFile(path string, fileroot string) RouterNode
+	
+	// RegisterRoute registers a new route with the given HTTP method, path and handler.
+	RegisterRoute(method, path string, h HttpHandle) RouterNode
+	
+	// SetNotFoundHandle sets a custom 404 handler for this group.
+	// This handler takes priority over the app-level NotFoundHandler.
+	// If a request path starts with the group's prefix but no route matches,
+	// this handler will be called instead of the global NotFoundHandler.
+	SetNotFoundHandle(handler StandardHandle) Group
+}
+
+// xGroup is the implementation of Group interface.
+type xGroup struct {
+	prefix           string
+	middlewares      []Middleware
+	allRouterExpress map[string]struct{}
+	server           *HttpServer
+	notFoundHandler  StandardHandle
+}
 
 func NewGroup(prefix string, server *HttpServer) Group {
 	g := &xGroup{prefix: prefix, server: server, allRouterExpress: make(map[string]struct{})}
@@ -119,3 +151,12 @@ func (g *xGroup) add(method, path string, handler HttpHandle) RouterNode {
 	node.Node().groupMiddlewares = g.middlewares
 	return node
 }
+
+// SetNotFoundHandle sets a custom 404 handler for this group.
+// This handler takes priority over the app-level NotFoundHandler.
+// If a request path starts with the group's prefix but no route matches,
+// this handler will be called instead of the global NotFoundHandler.
+func (g *xGroup) SetNotFoundHandle(handler StandardHandle) Group {
+	g.notFoundHandler = handler
+	return g
+}