diff --git a/README.md b/README.md
index 4e6b120..690fc57 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,7 @@ But still in early stage, feel free to fork or contribute to it.
 
 Thanks for your using.
 
-License under MIT.
\ No newline at end of file
+The notes are store in PostgreSQL, and I provided the schema in the hackmd_schema.sql.
+The users and sessions are store in mongoDB, which don't need schema, so just launch and connect it.
+
+License under MIT.