diff --git a/changelog.md b/changelog.md
index 833d4ad..6ce913c 100644
--- a/changelog.md
+++ b/changelog.md
@@ -106,26 +106,26 @@ b['1']['2'] = {'3':1}  # OK
     - [ ] amazon
 - [x] link to douban and amazon
 - export function:
-    - to [evernote](https://github.com/benhorvath/kindle2evernote/blob/master/kindle2evernote.py)
-    - to web html format
-    - pdf
-    - onenote
+    - [ ] to [evernote](https://github.com/benhorvath/kindle2evernote/blob/master/kindle2evernote.py)
+    - [ ] to web html format
+    - [ ] pdf
+    - [ ] onenote
     - [x] txt
     - [x] markdown
-- easily copy filter notes to clipboard
-- implement command line based on [argparse](https://www.jianshu.com/p/a41fbd4919f8)
+- [ ] easily copy filter notes to clipboard
+- [ ] implement command line based on [argparse](https://www.jianshu.com/p/a41fbd4919f8)
 - :x: mobi / epub reader 
-- import .azw3/.epub/.mobi file to kindle
-- [convert](https://github.com/jianyun8023/convert-ebook) .epub -> .mobi <br>
-          .azw3 -> .mobi <br>
-          .md   -> .mobi
+- [ ] import .azw3/.epub/.mobi file to kindle
+- [ ] [convert](https://github.com/jianyun8023/convert-ebook) .epub -> .mobi <br>
+    - [ ] .azw3 -> .mobi
+    - [ ] .md   -> .mobi
 - [x] parse /Volumes/Kindle/system/vocabulary/vocab.db
-- [hotkey](https://toolinbox.net/Klib/)
-- write [tutorial](https://help.knotesapp.com/docs/tutorial/)
-- search word in online dictionary
-- chrome extension
-- clean (sdr)
-- sync modify to kindle device
-- compare parse html info with xpath & beautisoap & regex
+- [ ] [hotkey](https://toolinbox.net/Klib/)
+- [ ] write [tutorial](https://help.knotesapp.com/docs/tutorial/)
+- [ ] search word in online dictionary
+- [ ] chrome extension
+- [ ] clean (sdr)
+- [ ] sync modify to kindle device
+- [ ] compare parse html info with xpath & beautisoap & regex