I have done lot of work on my site specially home page keywords but from last 2 months the ranking goes down day by day whereas other pages keywords are boost up on GOOGLE. I have regularly worked on those keywords like Bookmarking, Blog commenting, SMO, Article submission but no any improvement.
Kindly check my site and suggest me what can I do ? Is my keywords in Sandbox or anything else ??
Unfortunately, it seems you are doing all the right things. Just keep persevering and maybe you'll strike it lucky at the next google algorithm update. Be sure to really go strong on getting a constant stream of new backlinks always being added.