diff --git a/app_test.go b/app_test.go
index aa0a5ef72..2b8c8c9d2 100644
--- a/app_test.go
+++ b/app_test.go
@@ -2,7 +2,7 @@ package kratos
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"net/url"
 	"reflect"
 	"sync"
@@ -21,7 +21,7 @@ type mockRegistry struct {
 
 func (r *mockRegistry) Register(ctx context.Context, service *registry.ServiceInstance) error {
 	if service == nil || service.ID == "" {
-		return fmt.Errorf("no service id")
+		return errors.New("no service id")
 	}
 	r.lk.Lock()
 	defer r.lk.Unlock()
@@ -34,7 +34,7 @@ func (r *mockRegistry) Deregister(ctx context.Context, service *registry.Service
 	r.lk.Lock()
 	defer r.lk.Unlock()
 	if r.service[service.ID] == nil {
-		return fmt.Errorf("deregister service not found")
+		return errors.New("deregister service not found")
 	}
 	delete(r.service, service.ID)
 	return nil
diff --git a/contrib/registry/nacos/registry.go b/contrib/registry/nacos/registry.go
index 088cb8c28..1a3722b84 100644
--- a/contrib/registry/nacos/registry.go
+++ b/contrib/registry/nacos/registry.go
@@ -2,6 +2,7 @@ package nacos
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"net"
 	"net/url"
@@ -14,6 +15,8 @@ import (
 	"github.com/go-kratos/kratos/v2/registry"
 )
 
+var ErrServiceInstanceNameEmpty = errors.New("kratos/nacos: ServiceInstance.Name can not be empty")
+
 var (
 	_ registry.Registrar = (*Registry)(nil)
 	_ registry.Discovery = (*Registry)(nil)
@@ -82,7 +85,7 @@ func New(cli naming_client.INamingClient, opts ...Option) (r *Registry) {
 // Register the registration.
 func (r *Registry) Register(_ context.Context, si *registry.ServiceInstance) error {
 	if si.Name == "" {
-		return fmt.Errorf("kratos/nacos: serviceInstance.name can not be empty")
+		return ErrServiceInstanceNameEmpty
 	}
 	for _, endpoint := range si.Endpoints {
 		u, err := url.Parse(endpoint)
diff --git a/middleware/circuitbreaker/circuitbreaker_test.go b/middleware/circuitbreaker/circuitbreaker_test.go
index b7c2553ce..611419c78 100644
--- a/middleware/circuitbreaker/circuitbreaker_test.go
+++ b/middleware/circuitbreaker/circuitbreaker_test.go
@@ -5,7 +5,7 @@ import (
 	"errors"
 	"testing"
 
-	kratos_errors "github.com/go-kratos/kratos/v2/errors"
+	kratoserrors "github.com/go-kratos/kratos/v2/errors"
 	"github.com/go-kratos/kratos/v2/internal/group"
 	"github.com/go-kratos/kratos/v2/transport"
 )
@@ -62,7 +62,7 @@ func Test_Server(t *testing.T) {
 		return "Hello valid", nil
 	}
 	nextInvalid := func(ctx context.Context, req interface{}) (interface{}, error) {
-		return nil, kratos_errors.InternalServer("", "")
+		return nil, kratoserrors.InternalServer("", "")
 	}
 
 	ctx := transport.NewClientContext(context.Background(), &transportMock{})
diff --git a/middleware/validate/validate_test.go b/middleware/validate/validate_test.go
index f1597820a..34fc33497 100644
--- a/middleware/validate/validate_test.go
+++ b/middleware/validate/validate_test.go
@@ -2,10 +2,10 @@ package validate
 
 import (
 	"context"
-	"fmt"
+	"errors"
 	"testing"
 
-	"github.com/go-kratos/kratos/v2/errors"
+	kratoserrors "github.com/go-kratos/kratos/v2/errors"
 	"github.com/go-kratos/kratos/v2/middleware"
 )
 
@@ -18,7 +18,7 @@ type protoVali struct {
 
 func (v protoVali) Validate() error {
 	if v.name == "" || v.age < 0 {
-		return fmt.Errorf("err")
+		return errors.New("err")
 	}
 	return nil
 }
@@ -35,7 +35,7 @@ func TestTable(t *testing.T) {
 		t.Run(test.name, func(t *testing.T) {
 			v := Validator()(mock)
 			_, err := v(context.Background(), test)
-			if want, have := test.isErr, errors.IsBadRequest(err); want != have {
+			if want, have := test.isErr, kratoserrors.IsBadRequest(err); want != have {
 				t.Errorf("fail data %v, want %v, have %v", test, want, have)
 			}
 		})
diff --git a/transport/grpc/resolver/direct/builder_test.go b/transport/grpc/resolver/direct/builder_test.go
index 1cd6bf402..82cd8cd1f 100644
--- a/transport/grpc/resolver/direct/builder_test.go
+++ b/transport/grpc/resolver/direct/builder_test.go
@@ -1,7 +1,7 @@
 package direct
 
 import (
-	"fmt"
+	"errors"
 	"reflect"
 	"testing"
 
@@ -22,7 +22,7 @@ type mockConn struct {
 
 func (m *mockConn) UpdateState(resolver.State) error {
 	if m.needUpdateStateErr {
-		return fmt.Errorf("mock test needUpdateStateErr")
+		return errors.New("mock test needUpdateStateErr")
 	}
 	return nil
 }
diff --git a/transport/http/client_test.go b/transport/http/client_test.go
index 4ee00456f..ab8031dd5 100644
--- a/transport/http/client_test.go
+++ b/transport/http/client_test.go
@@ -33,7 +33,7 @@ type mockCallOption struct {
 
 func (x *mockCallOption) before(info *callInfo) error {
 	if x.needErr {
-		return fmt.Errorf("option need return err")
+		return errors.New("option need return err")
 	}
 	return nil
 }
@@ -357,7 +357,7 @@ func TestNewClient(t *testing.T) {
 		t.Error("err should be equal to callOption err")
 	}
 	client.opts.encoder = func(ctx context.Context, contentType string, in interface{}) (body []byte, err error) {
-		return nil, fmt.Errorf("mock test encoder error")
+		return nil, errors.New("mock test encoder error")
 	}
 	err = client.Invoke(context.Background(), "POST", "/go", map[string]string{"name": "kratos"}, nil, EmptyCallOption{})
 	if err == nil {
diff --git a/transport/http/context_test.go b/transport/http/context_test.go
index 3b7466bf0..b440e9df7 100644
--- a/transport/http/context_test.go
+++ b/transport/http/context_test.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"context"
 	"errors"
-	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -92,7 +91,7 @@ func TestContextResponse(t *testing.T) {
 	if err != nil {
 		t.Errorf("expected %v, got %v", nil, err)
 	}
-	needErr := fmt.Errorf("some error")
+	needErr := errors.New("some error")
 	err = w.Returns(map[string]string{}, needErr)
 	if !errors.Is(err, needErr) {
 		t.Errorf("expected %v, got %v", needErr, err)
diff --git a/transport/http/resolver_test.go b/transport/http/resolver_test.go
index 27473d12b..e95d8850b 100644
--- a/transport/http/resolver_test.go
+++ b/transport/http/resolver_test.go
@@ -73,7 +73,7 @@ const errServiceName = "needErr"
 
 func (d *mockDiscoveries) Watch(ctx context.Context, serviceName string) (registry.Watcher, error) {
 	if serviceName == errServiceName {
-		return nil, fmt.Errorf("mock test service name watch err")
+		return nil, errors.New("mock test service name watch err")
 	}
 	return &mockWatch{ctx: ctx, isSecure: d.isSecure, nextErr: d.nextErr, stopErr: d.stopErr}, nil
 }
@@ -116,7 +116,7 @@ func (m *mockWatch) Next() ([]*registry.ServiceInstance, error) {
 
 func (m *mockWatch) Stop() error {
 	if m.stopErr {
-		return fmt.Errorf("mock test error")
+		return errors.New("mock test error")
 	}
 	// 标记 next 需要报错
 	m.nextErr = true
diff --git a/transport/http/server_test.go b/transport/http/server_test.go
index 05bc8399e..0d4be88bd 100644
--- a/transport/http/server_test.go
+++ b/transport/http/server_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"crypto/tls"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -13,8 +14,7 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-kratos/kratos/v2/errors"
-
+	kratoserrors "github.com/go-kratos/kratos/v2/errors"
 	"github.com/go-kratos/kratos/v2/internal/host"
 )
 
@@ -49,9 +49,9 @@ func TestServeHTTP(t *testing.T) {
 	mux := NewServer(Listener(ln))
 	mux.HandleFunc("/index", h)
 	mux.Route("/errors").GET("/cause", func(ctx Context) error {
-		return errors.BadRequest("xxx", "zzz").
+		return kratoserrors.BadRequest("xxx", "zzz").
 			WithMetadata(map[string]string{"foo": "bar"}).
-			WithCause(fmt.Errorf("error cause"))
+			WithCause(errors.New("error cause"))
 	})
 	if err = mux.WalkRoute(func(r RouteInfo) error {
 		t.Logf("WalkRoute: %+v", r)
@@ -65,7 +65,7 @@ func TestServeHTTP(t *testing.T) {
 	srv := http.Server{Handler: mux}
 	go func() {
 		if err := srv.Serve(ln); err != nil {
-			if errors.Is(err, http.ErrServerClosed) {
+			if kratoserrors.Is(err, http.ErrServerClosed) {
 				return
 			}
 			panic(err)
@@ -87,9 +87,9 @@ func TestServer(t *testing.T) {
 		_ = json.NewEncoder(w).Encode(testData{Path: r.RequestURI})
 	})
 	srv.Route("/errors").GET("/cause", func(ctx Context) error {
-		return errors.BadRequest("xxx", "zzz").
+		return kratoserrors.BadRequest("xxx", "zzz").
 			WithMetadata(map[string]string{"foo": "bar"}).
-			WithCause(fmt.Errorf("error cause"))
+			WithCause(errors.New("error cause"))
 	})
 
 	if e, err := srv.Endpoint(); err != nil || e == nil || strings.HasSuffix(e.Host, ":0") {
@@ -135,7 +135,7 @@ func testAccept(t *testing.T, srv *Server) {
 		}
 		req.Header.Set("Content-Type", test.contentType)
 		resp, err := client.Do(req)
-		if errors.Code(err) != 400 {
+		if kratoserrors.Code(err) != 400 {
 			t.Errorf("expected 400 got %v", err)
 		}
 		if err == nil {
@@ -205,7 +205,7 @@ func testClient(t *testing.T, srv *Server) {
 			t.Fatal(err)
 		}
 		resp, err := client.Do(req)
-		if errors.Code(err) != test.code {
+		if kratoserrors.Code(err) != test.code {
 			t.Fatalf("want %v, but got %v", test, err)
 		}
 		if err != nil {
@@ -231,7 +231,7 @@ func testClient(t *testing.T, srv *Server) {
 	for _, test := range tests {
 		var res testData
 		err := client.Invoke(context.Background(), test.method, test.path, nil, &res)
-		if errors.Code(err) != test.code {
+		if kratoserrors.Code(err) != test.code {
 			t.Fatalf("want %v, but got %v", test, err)
 		}
 		if err != nil {