diff --git a/middleware/metadata/metadata.go b/middleware/metadata/metadata.go
index 5c29189f9..da9e43a96 100644
--- a/middleware/metadata/metadata.go
+++ b/middleware/metadata/metadata.go
@@ -51,16 +51,19 @@ func Server(opts ...Option) middleware.Middleware {
 	}
 	return func(handler middleware.Handler) middleware.Handler {
 		return func(ctx context.Context, req interface{}) (reply interface{}, err error) {
-			if tr, ok := transport.FromServerContext(ctx); ok {
-				md := options.md.Clone()
-				header := tr.RequestHeader()
-				for _, k := range header.Keys() {
-					if options.hasPrefix(k) {
-						md.Set(k, header.Get(k))
-					}
+			tr, ok := transport.FromServerContext(ctx)
+			if !ok {
+				return handler(ctx, req)
+			}
+
+			md := options.md.Clone()
+			header := tr.RequestHeader()
+			for _, k := range header.Keys() {
+				if options.hasPrefix(k) {
+					md.Set(k, header.Get(k))
 				}
-				ctx = metadata.NewServerContext(ctx, md)
 			}
+			ctx = metadata.NewServerContext(ctx, md)
 			return handler(ctx, req)
 		}
 	}
@@ -76,25 +79,28 @@ func Client(opts ...Option) middleware.Middleware {
 	}
 	return func(handler middleware.Handler) middleware.Handler {
 		return func(ctx context.Context, req interface{}) (reply interface{}, err error) {
-			if tr, ok := transport.FromClientContext(ctx); ok {
-				header := tr.RequestHeader()
-				// x-md-local-
-				for k, v := range options.md {
+			tr, ok := transport.FromClientContext(ctx)
+			if !ok {
+				return handler(ctx, req)
+			}
+
+			header := tr.RequestHeader()
+			// x-md-local-
+			for k, v := range options.md {
+				header.Set(k, v)
+			}
+			if md, ok := metadata.FromClientContext(ctx); ok {
+				for k, v := range md {
 					header.Set(k, v)
 				}
-				if md, ok := metadata.FromClientContext(ctx); ok {
-					for k, v := range md {
+			}
+			// x-md-global-
+			if md, ok := metadata.FromServerContext(ctx); ok {
+				for k, v := range md {
+					if options.hasPrefix(k) {
 						header.Set(k, v)
 					}
 				}
-				// x-md-global-
-				if md, ok := metadata.FromServerContext(ctx); ok {
-					for k, v := range md {
-						if options.hasPrefix(k) {
-							header.Set(k, v)
-						}
-					}
-				}
 			}
 			return handler(ctx, req)
 		}
diff --git a/middleware/metadata/metadata_test.go b/middleware/metadata/metadata_test.go
index e46a94f50..b083f9c10 100644
--- a/middleware/metadata/metadata_test.go
+++ b/middleware/metadata/metadata_test.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"net/http"
+	"reflect"
 	"testing"
 
 	"github.com/go-kratos/kratos/v2/metadata"
@@ -33,15 +34,18 @@ func (tr *testTransport) Operation() string               { return "" }
 func (tr *testTransport) RequestHeader() transport.Header { return tr.header }
 func (tr *testTransport) ReplyHeader() transport.Header   { return tr.header }
 
+var (
+	globalKey   = "x-md-global-key"
+	globalValue = "global-value"
+	localKey    = "x-md-local-key"
+	localValue  = "local-value"
+	customKey   = "x-md-local-custom"
+	customValue = "custom-value"
+	constKey    = "x-md-local-const"
+	constValue  = "x-md-local-const"
+)
+
 func TestSever(t *testing.T) {
-	var (
-		globalKey   = "x-md-global-key"
-		globalValue = "global-value"
-		localKey    = "x-md-local-key"
-		localValue  = "local-value"
-		constKey    = "x-md-local-const"
-		constValue  = "x-md-local-const"
-	)
 	hs := func(ctx context.Context, in interface{}) (interface{}, error) {
 		md, ok := metadata.FromServerContext(ctx)
 		if !ok {
@@ -75,16 +79,6 @@ func TestSever(t *testing.T) {
 }
 
 func TestClient(t *testing.T) {
-	var (
-		globalKey   = "x-md-global-key"
-		globalValue = "global-value"
-		localKey    = "x-md-local-key"
-		localValue  = "local-value"
-		customKey   = "x-md-local-custom"
-		customValue = "custom-value"
-		constKey    = "x-md-local-const"
-		constValue  = "x-md-local-const"
-	)
 	hs := func(ctx context.Context, in interface{}) (interface{}, error) {
 		tr, ok := transport.FromClientContext(ctx)
 		if !ok {
@@ -127,13 +121,52 @@ func TestClient(t *testing.T) {
 	}
 }
 
-func Test_WithPropagatedPrefix(t *testing.T) {
-	o := &options{
+func TestWithConstants(t *testing.T) {
+	md := metadata.Metadata{
+		constKey: constValue,
+	}
+	options := &options{
+		md: metadata.Metadata{
+			"override": "override",
+		},
+	}
+
+	WithConstants(md)(options)
+	if !reflect.DeepEqual(md, options.md) {
+		t.Errorf("want: %v, got: %v", md, options.md)
+	}
+}
+
+func TestOptions_WithPropagatedPrefix(t *testing.T) {
+	options := &options{
 		prefix: []string{"override"},
 	}
-	WithPropagatedPrefix("something", "another")(o)
+	prefixes := []string{"something", "another"}
 
-	if len(o.prefix) != 2 {
+	WithPropagatedPrefix(prefixes...)(options)
+	if !reflect.DeepEqual(prefixes, options.prefix) {
 		t.Error("The prefix must be overridden.")
 	}
 }
+
+func TestOptions_hasPrefix(t *testing.T) {
+	tests := []struct {
+		name    string
+		options *options
+		key     string
+		exists  bool
+	}{
+		{"exists key upper", &options{prefix: []string{"prefix"}}, "PREFIX_true", true},
+		{"exists key lower", &options{prefix: []string{"prefix"}}, "prefix_true", true},
+		{"not exists key upper", &options{prefix: []string{"prefix"}}, "false_PREFIX", false},
+		{"not exists key lower", &options{prefix: []string{"prefix"}}, "false_prefix", false},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			exists := test.options.hasPrefix(test.key)
+			if test.exists != exists {
+				t.Errorf("key: '%sr', not exists prefixs: %v", test.key, test.options.prefix)
+			}
+		})
+	}
+}