diff --git a/cflag/ext.go b/cflag/ext.go
index 7287838a2..25d8e702f 100644
--- a/cflag/ext.go
+++ b/cflag/ext.go
@@ -255,6 +255,13 @@ func (s *String) Ints(sep string) []int {
 //
 // Implemented the flag.Value interface.
 //
+// Usage:
+//
+//		type myOpts struct {
+//			vars cflag.KVString
+//		}
+//	 var mo &myOpts{ vars: cflag.NewKVString() }
+//
 // Example:
 //
 //	--var name=inhere => string map {name:inhere}
@@ -266,10 +273,16 @@ type KVString struct {
 
 // NewKVString instance
 func NewKVString() KVString {
-	return KVString{
-		Sep:  comdef.EqualStr,
-		SMap: make(maputil.SMap),
+	return *(&KVString{}).Init()
+}
+
+// Init settings
+func (s *KVString) Init() *KVString {
+	if s.Sep == "" {
+		s.Sep = comdef.EqualStr
+		s.SMap = make(maputil.SMap)
 	}
+	return s
 }
 
 // Get value
@@ -285,6 +298,8 @@ func (s *KVString) Data() maputil.SMap {
 // Set new value, will check value is right
 func (s *KVString) Set(value string) error {
 	if value != "" {
+		s.Init()
+
 		key, val := strutil.SplitKV(value, s.Sep)
 		if key != "" {
 			s.SMap[key] = val
diff --git a/cflag/ext_test.go b/cflag/ext_test.go
index 348120be8..bb880b901 100644
--- a/cflag/ext_test.go
+++ b/cflag/ext_test.go
@@ -30,7 +30,8 @@ func TestConfString_Set(t *testing.T) {
 	cs = cflag.ConfString{}
 	err := cs.Set("name=inhere;age=123")
 	assert.NoErr(t, err)
-	assert.NotEmpty(t, cs.Data())
+	assert.NotEmpty(t, cs.Get())
+	assert.NotEmpty(t, cs.String())
 	assert.Eq(t, "inhere", cs.Str("name"))
 	assert.Eq(t, 123, cs.Int("age"))
 }
@@ -41,8 +42,11 @@ func TestKVString_Set(t *testing.T) {
 
 	assert.NoErr(t, kv.Set("age=234"))
 	assert.NotEmpty(t, kv.Data())
+	assert.NotEmpty(t, kv.Get())
 	assert.Eq(t, 234, kv.Int("age"))
 	assert.Eq(t, "{age:234}", kv.String())
+	assert.False(t, kv.IsEmpty())
+	assert.True(t, kv.IsRepeatable())
 
 	assert.NoErr(t, kv.Set("name=inhere"))
 	assert.Eq(t, "inhere", kv.Str("name"))