diff --git a/README.md b/README.md
index a7df471..766cc54 100755
--- a/README.md
+++ b/README.md
@@ -172,7 +172,41 @@ book =
 
 ```
 words datastructure achieved from database sqlite2
+/Volumes/Kindle/system/vocabulary/vocab.db
+```
 
+```
+table: BOOK_INFO
+  id         - book key, CR!NYRVJ9BT315PKFRS9B9KVB0XF213:6F1EB741
+  asin       x
+  guid       x
+  lang       x zh/en
+  title      - bookname
+  authors    - author
+```
+
+table: LOOKUPS
+  id         x lookups key, CR!NYRVJ9BT315PKFRS9B9KVB0XF213:6F1EB741:xxx
+  word_key   - zh:当
+  book_key   - book key, like CR!NYRVJ9BT315PKFRS9B9KVB0XF213:6F1EB741
+  dict_key   x
+  pos        - position, like AYkJAAAAAAAA:28781, 115907
+  usage      - usage
+  timestamp  - 1566738399454
+```
+
+```
+table: WORDS
+  id         - zh:当
+  word       x 当
+  stem       x
+  lang       - zh/en
+  category   - 0 learning, 100 mastered
+  timestamp  x 1591141963703
+  profileid  x
+```
+
+```
 words_data = [bookinfo, words, lookups]
 bookinfo = { 'book_key': {
              'bookname':'bookname_xxx',