Go to the 'user' folder –>Library –>Application Support –> Google – Chrome –> Default.
Copy the bookmark.bak to bookmarks.
This will make the backup copy into the current copy. Then restart your chrome, and the bookmarks should be restored.
Windows XP
Go to C:\Documents and Settings\<your_username>\Local Settings\Application Data\Google\Chrome\User Data\Default\on Vista: C:\Users\<your_username>\AppData\Local\Google\Chrome\User Data\Default\
Copy bookmark.bak to bookmarks.
Windows 7
Go to C:\Users\<YOUR USERNAME>\AppData\Local\Google\Chrome\User Data\Default
Copy the Bookmarks.bak file to a safe location ( I copied the “bookmarks.bak” file to my desktop).
Close Chrome.
Rename the “Bookmarks.bak” file you just copied to “Bookmarks” and copy it back in to that directory, overwriting the original one.