diff --git a/README.ko.md b/README.ko.md
index 874cd86..a1b82b9 100644
--- a/README.ko.md
+++ b/README.ko.md
@@ -56,7 +56,10 @@ qDebug() << var; // 값 표시
 - 유니코드 테스트 (파일 이름 :cloud:, 파일 경로 :cloud:, 자료값 :sunny:)
 
 ## 업그레이드 할 일
-- xlsx의 암복호화 기능 개발
+- [업그레드 할 일](ToUpgrade.md) 참조.
+
+## 컨트리뷰터
+- [Contributors](https://github.com/j2doll/QXlsx/graphs/contributors) 참조.
 
 ## 라이센스와 링크
 - QXlsx 는 MIT 라이센스 입니다. [https://github.com/j2doll/QXlsx](https://github.com/j2doll/QXlsx)
diff --git a/README.md b/README.md
index f1742b0..ac87df1 100644
--- a/README.md
+++ b/README.md
@@ -56,7 +56,10 @@ qDebug() << var; // display value
 - Unicode test (filename :cloud:, filepath :cloud:, data value :sunny:)
 
 ## To Upgrade
-- Develop the encryption function of xlsx
+- See [what to upgrade](ToUpgrade.md).
+
+## Contributions
+- See [contributors](https://github.com/j2doll/QXlsx/graphs/contributors).
 
 ## License and links
 - QXlsx is under MIT license. [https://github.com/j2doll/QXlsx](https://github.com/j2doll/QXlsx)
diff --git a/ToUpgrade.md b/ToUpgrade.md
new file mode 100644
index 0000000..1f7c3ee
--- /dev/null
+++ b/ToUpgrade.md
@@ -0,0 +1,2 @@
+# To Upgrade
+- Develop the encryption function of xlsx