diff --git a/maps/hash_map.go b/maps/hash_map.go
index 2e893db..ace0b0c 100644
--- a/maps/hash_map.go
+++ b/maps/hash_map.go
@@ -8,12 +8,13 @@ type hashMap[K constraints.Ordered, V any] struct {
 	m map[K]V
 }
 
-func NewHashMap[K constraints.Ordered, V any]() *hashMap[K, V] {
+func NewHashMap[K constraints.Ordered, V any](maps ...map[K]V) *hashMap[K, V] {
 	return &hashMap[K, V]{m: make(map[K]V)}
 }
 
-func newHashMap[K constraints.Ordered, V any](maps ...map[K]V) *hashMap[K, V] {
-	return &hashMap[K, V]{m: Merge(maps...)}
+// synchronized
+func (m *hashMap[K, V]) Synchronized() *hashMap[K, V] {
+	return m
 }
 
 func (m *hashMap[K, V]) Set(key K, value V) {
@@ -92,10 +93,5 @@ func (m *hashMap[K, V]) Count() int {
 }
 
 func (m *hashMap[K, V]) Clone() Map[K, V] {
-	r := make(map[K]V, len(m.m))
-	for k, v := range m.m {
-		r[k] = v
-	}
-
-	return newHashMap(r)
+	return NewHashMap(m.ToMap())
 }
diff --git a/maps/map.go b/maps/map.go
index aa688f5..77d51f4 100644
--- a/maps/map.go
+++ b/maps/map.go
@@ -40,10 +40,10 @@ func Merge[K comparable, V any](mm ...map[K]V) map[K]V {
 // 按照键值生成字符串
 func Join[K constraints.Ordered, V any](m Map[K, V], sep string, f func(k K, v V) string) string {
 	slice := make([]string, 0, m.Count())
-	for _, k := range m.Keys() {
-		v, _ := m.Get(k)
+
+	m.ForEach(func(k K, v V) {
 		slice = append(slice, f(k, v))
-	}
+	})
 
 	return strings.Join(slice, sep)
 }
diff --git a/maps/rwlock_map.go b/maps/rwlock_map.go
index 96ee914..e2d03a8 100644
--- a/maps/rwlock_map.go
+++ b/maps/rwlock_map.go
@@ -15,7 +15,7 @@ type rw_map[K constraints.Ordered, V any] struct {
 
 func NewRWMap[K constraints.Ordered, V any](maps ...map[K]V) *rw_map[K, V] {
 	merged := Merge(maps...)
-	return &rw_map[K, V]{m: newHashMap(merged)}
+	return &rw_map[K, V]{m: NewHashMap(merged)}
 }
 
 func newRWMap[K constraints.Ordered, V any](m Map[K, V]) *rw_map[K, V] {
diff --git a/maps/sort_map.go b/maps/sort_map.go
index 6b2c7f2..42c7a5d 100644
--- a/maps/sort_map.go
+++ b/maps/sort_map.go
@@ -13,6 +13,7 @@ var (
 )
 
 type SortedMap[K constraints.Ordered, V any] interface {
+	Map[K, V]
 	Asc() SortedMap[K, V]
 	Desc() SortedMap[K, V]
 }
@@ -26,7 +27,7 @@ func NewSortedMap[K constraints.Ordered, V any](maps ...map[K]V) *sorted_map[K,
 	merged := Merge(maps...)
 	return &sorted_map[K, V]{
 		keys: keys(merged),
-		maps: newHashMap(merged),
+		maps: NewHashMap(merged),
 	}
 }
 
@@ -35,11 +36,11 @@ func NewSortedByMap[K constraints.Ordered, V any](m Map[K, V]) *sorted_map[K, V]
 }
 
 func (m *sorted_map[K, V]) Get(key K) (V, bool) {
-	return m.Get(key)
+	return m.maps.Get(key)
 }
 
 func (m *sorted_map[K, V]) Set(key K, value V) {
-	m.Set(key, value)
+	m.maps.Set(key, value)
 	m.keys = append(m.keys, key)
 }
 
@@ -85,11 +86,15 @@ func (m *sorted_map[K, V]) Iter() <-chan *Entry[K, V] {
 }
 
 func (m *sorted_map[K, V]) ForEach(f func(K, V)) {
-	m.maps.ForEach(f)
+	for _, k := range m.keys {
+		if v, ok := m.Get(k); ok {
+			f(k, v)
+		}
+	}
 }
 
 func (m *sorted_map[K, V]) Exist(key K) bool {
-	return m.Exist(key)
+	return m.maps.Exist(key)
 }
 
 func (m *sorted_map[K, V]) Keys() []K {
diff --git a/maps/sorted_map_test.go b/maps/sorted_map_test.go
new file mode 100644
index 0000000..fb30728
--- /dev/null
+++ b/maps/sorted_map_test.go
@@ -0,0 +1,24 @@
+package maps
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestSortMapConvert(t *testing.T) {
+	var m = NewSortedMap(map[string]any{"aaa": "bbb"}).Asc()
+
+	var c Map[string, any] = m
+
+	t.Log(Join(c, " ", func(k string, v any) string {
+		return fmt.Sprintf("%s=%v", k, v)
+	}))
+}
+
+func TestSortedJoin(t *testing.T) {
+	var m = NewSortedMap(map[string]any{"b": "b", "a": "a", "d": "d", "c": "c"}).Asc()
+
+	t.Log(Join[string, any](m, "&", func(k string, v any) string {
+		return fmt.Sprintf("%s=%v", k, v)
+	}))
+}