diff --git a/header.go b/header.go
new file mode 100644
index 00000000..ac1be32b
--- /dev/null
+++ b/header.go
@@ -0,0 +1,41 @@
+/*
+  GoLang code created by Jirawat Harnsiriwatanakit https://github.com/kazekim
+*/
+
+package req
+
+import "encoding/json"
+
+// Header represents http request header
+type Header map[string]string
+
+func (h Header) Clone() Header {
+	if h == nil {
+		return nil
+	}
+	hh := Header{}
+	for k, v := range h {
+		hh[k] = v
+	}
+	return hh
+}
+
+// ParseStruct parse struct into header
+func ParseStruct(h Header, v interface{}) Header {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return h
+	}
+
+	err = json.Unmarshal(data, &h)
+	return h
+}
+
+// HeaderFromStruct init header from struct
+func HeaderFromStruct(v interface{}) Header {
+
+	var header Header
+	header = ParseStruct(header, v)
+	return header
+}
+
diff --git a/header_test.go b/header_test.go
new file mode 100644
index 00000000..5e56fac4
--- /dev/null
+++ b/header_test.go
@@ -0,0 +1,47 @@
+/*
+  GoLang code created by Jirawat Harnsiriwatanakit https://github.com/kazekim
+*/
+
+package req
+
+import "testing"
+
+func TestParseStruct(t *testing.T) {
+
+	type HeaderStruct struct {
+		UserAgent     string `json:"User-Agent"`
+		Authorization string `json:"Authorization"`
+	}
+
+	h := HeaderStruct{
+		"V1.0.0",
+		"roc",
+	}
+
+	var header Header
+	header = ParseStruct(header, h)
+
+	if header["User-Agent"] != h.UserAgent && header["Authorization"] != h.Authorization {
+		t.Fatal("struct parser for header is not working")
+	}
+
+}
+
+func TestHeaderFromStruct(t *testing.T) {
+
+	type HeaderStruct struct {
+		UserAgent string `json:"User-Agent"`
+		Authorization string `json:"Authorization"`
+	}
+
+	h := HeaderStruct{
+		"V1.0.0",
+		"roc",
+	}
+
+	header := HeaderFromStruct(h)
+
+	if header["User-Agent"] != h.UserAgent && header["Authorization"] != h.Authorization {
+		t.Fatal("struct parser for header is not working")
+	}
+}
diff --git a/req.go b/req.go
index b0424a84..01937f04 100644
--- a/req.go
+++ b/req.go
@@ -34,39 +34,6 @@ const (
 	LstdFlags = LreqHead | LreqBody | LrespHead | LrespBody
 )
 
-// Header represents http request header
-type Header map[string]string
-
-func (h Header) Clone() Header {
-	if h == nil {
-		return nil
-	}
-	hh := Header{}
-	for k, v := range h {
-		hh[k] = v
-	}
-	return hh
-}
-
-// ParseStruct parse struct into header
-func ParseStruct(h Header, v interface{}) Header {
-	data, err := json.Marshal(v)
-	if err != nil {
-		return h
-	}
-
-	err = json.Unmarshal(data, &h)
-	return h
-}
-
-// HeaderFromStruct init header from struct
-func HeaderFromStruct(v interface{}) Header {
-
-	var header Header
-	header = ParseStruct(header, v)
-	return header
-}
-
 // Param represents  http request param
 type Param map[string]interface{}
 
diff --git a/req_test.go b/req_test.go
index f37ad4fe..a863941a 100644
--- a/req_test.go
+++ b/req_test.go
@@ -267,46 +267,6 @@ func TestHeader(t *testing.T) {
 	}
 }
 
-func TestParseStruct(t *testing.T) {
-
-	type HeaderStruct struct {
-		UserAgent     string `json:"User-Agent"`
-		Authorization string `json:"Authorization"`
-	}
-
-	h := HeaderStruct{
-		"V1.0.0",
-		"roc",
-	}
-
-	var header Header
-	header = ParseStruct(header, h)
-
-	if header["User-Agent"] != "V1.0.0" && header["Authorization"] != "roc" {
-		t.Fatal("struct parser for header is not working")
-	}
-
-}
-
-func TestHeaderFromStruct(t *testing.T) {
-
-	type HeaderStruct struct {
-		UserAgent string `json:"User-Agent"`
-		Authorization string `json:"Authorization"`
-	}
-
-	h := HeaderStruct{
-		"V1.0.0",
-		"roc",
-	}
-
-	header := HeaderFromStruct(h)
-
-	if header["User-Agent"] != "V1.0.0" && header["Authorization"] != "roc" {
-		t.Fatal("struct parser for header is not working")
-	}
-}
-
 func TestUpload(t *testing.T) {
 	str := "hello req"
 	file := ioutil.NopCloser(strings.NewReader(str))