diff --git a/dotweb.go b/dotweb.go
index 9f42176..949c5b5 100644
--- a/dotweb.go
+++ b/dotweb.go
@@ -563,11 +563,10 @@ func (app *DotWeb) initBindMiddleware() {
 
 	// bind group middlewares
 	for _, g := range app.HttpServer.groups {
-		xg := g.(*xGroup)
-		if len(xg.middlewares) <= 0 {
+		if len(g.middlewares) <= 0 {
 			continue
 		}
-		for fullExpress, _ := range xg.allRouterExpress {
+		for fullExpress, _ := range g.allRouterExpress {
 			expresses := strings.Split(fullExpress, routerExpressSplit)
 			if len(expresses) < 2 {
 				continue
@@ -576,7 +575,7 @@ func (app *DotWeb) initBindMiddleware() {
 			if node == nil {
 				continue
 			}
-			node.groupMiddlewares = xg.middlewares
+			node.groupMiddlewares = g.middlewares
 			for _, m := range node.groupMiddlewares {
 				if m.HasExclude() && m.ExistsExcludeRouter(node.fullPath) {
 					app.Logger().Debug("DotWeb initBindMiddleware [group] "+fullExpress+" "+reflect.TypeOf(m).String()+" exclude", LogTarget_HttpServer)
diff --git a/group.go b/group.go
index 2e8f516..55836d4 100644
--- a/group.go
+++ b/group.go
@@ -15,12 +15,14 @@ type (
 		PUT(path string, h HttpHandle) RouterNode
 		ServerFile(path string, fileroot string) RouterNode
 		RegisterRoute(method, path string, h HttpHandle) RouterNode
+		SetNotFoundHandle(handler StandardHandle) Group
 	}
 	xGroup struct {
 		prefix           string
 		middlewares      []Middleware
 		allRouterExpress map[string]struct{}
 		server           *HttpServer
+		notFoundHandler  StandardHandle
 	}
 )
 
@@ -119,3 +121,10 @@ func (g *xGroup) add(method, path string, handler HttpHandle) RouterNode {
 	node.Node().groupMiddlewares = g.middlewares
 	return node
 }
+
+// SetNotFoundHandle sets custom 404 handler for this group.
+// This handler takes priority over the app-level NotFoundHandler.
+func (g *xGroup) SetNotFoundHandle(handler StandardHandle) Group {
+	g.notFoundHandler = handler
+	return g
+}
diff --git a/router.go b/router.go
index 4ae3b87..6b7d2ae 100644
--- a/router.go
+++ b/router.go
@@ -272,6 +272,14 @@ func (r *router) ServeHTTP(ctx Context) {
 	}
 
 	// Handle 404
+	// Check if request path matches any group prefix and use group's NotFoundHandler
+	for _, g := range r.server.groups {
+		if strings.HasPrefix(path, g.prefix) && g.notFoundHandler != nil {
+			g.notFoundHandler(ctx)
+			return
+		}
+	}
+	// Fall back to app-level NotFoundHandler
 	if r.server.DotApp.NotFoundHandler != nil {
 		r.server.DotApp.NotFoundHandler(ctx)
 	}
diff --git a/server.go b/server.go
index af332da..b2b19ca 100644
--- a/server.go
+++ b/server.go
@@ -30,7 +30,7 @@ type (
 	HttpServer struct {
 		stdServer      *http.Server
 		router         Router
-		groups         []Group
+		groups         []*xGroup
 		Modules        []*HttpModule
 		DotApp         *DotWeb
 		Validator      Validator