diff --git a/README.md b/README.md
index a06018a..d9672bf 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,7 @@
 - [ ] [附录:文档注释](docs/book/Appendix-Javadoc.md)
 - [ ] [附录:对象传递和返回](docs/book/Appendix-Passing-and-Returning-Objects.md)
 - [ ] [附录:流式IO](docs/book/Appendix-IO-Streams.md)
-- [ ] [附录:标准IO](docs/book/Appendix-Standard-IO.md)
+- [x] [附录:标准IO](docs/book/Appendix-Standard-IO.md)
 - [x] [附录:新IO](docs/book/Appendix-New-IO.md)
 - [x] [附录:理解equals和hashCode方法](docs/book/Appendix-Understanding-equals-and-hashCode.md)
 - [x] [附录:集合主题](docs/book/Appendix-Collection-Topics.md)