diff --git a/parser.go b/parser.go
index 2e5060a..cfce95d 100644
--- a/parser.go
+++ b/parser.go
@@ -32,12 +32,11 @@ func (JsonParser) Unmarshal(bodyType EntryMark, BodyEntry map[string]any) io.Rea
 	case BytesEntryType:
 		return bytes.NewReader(BodyEntry[BytesEntryType.string()].([]byte))
 	case ModelEntryType:
-		jsonData, err := json.Marshal(BodyEntry[BytesEntryType.string()])
+		jsonData, err := json.Marshal(BodyEntry[ModelEntryType.string()])
 		if err == nil {
 			return bytes.NewReader(jsonData)
-		} else {
-			return strings.NewReader("{}")
 		}
+		return strings.NewReader("{}")
 	case MapEntryType:
 		jsonData, err := json.Marshal(BodyEntry)
 		if err == nil {
@@ -81,7 +80,7 @@ func (f *FormDataParser) Unmarshal(bodyType EntryMark, BodyEntry map[string]any)
 		return strings.NewReader(BodyEntry[StringEntryType.string()].(string))
 	case BytesEntryType:
 		f.ContentType = formDataType
-		return bytes.NewReader(BodyEntry[StringEntryType.string()].([]byte))
+		return bytes.NewReader(BodyEntry[BytesEntryType.string()].([]byte))
 	default:
 		body, f.ContentType = multipartCommonParse(BodyEntry)
 	}
diff --git a/simpleRequest_test.go b/simpleRequest_test.go
index 40648b2..f98d023 100644
--- a/simpleRequest_test.go
+++ b/simpleRequest_test.go
@@ -67,3 +67,20 @@ func TestPost_withSets(t *testing.T) {
 		t.Log(string(result))
 	}
 }
+
+func TestPost_withSetModel(t *testing.T) {
+	go httpserver()
+
+	var r = NewRequest()
+	r.Headers().ConentType_json()
+	var entry = api{
+		Name: "JJXu",
+	}
+	r.Body().SetModel(&entry)
+	result, err := r.POST("http://localhost:8989/")
+	if err != nil {
+		t.Error(err.Error())
+	} else {
+		t.Log(string(result))
+	}
+}