I applied for Google Adsense, but they disapproved due to following reason
-does not meet the google webmaster guidelines. More specificly my site does not add a value and does not have unique content.
How can I get the approval.
Please explain.
Well, that basically says it all right there. If you are using others content (rss feeds, others articles, duplicated content from other sites, etc.) you will be declined.
In order for a sites content to be viable, it needs to be UNIQUE, meaning you need to at least try to write it all yourself in a way that is not found on another site.
If you want to check your content to see if it's duplicated somewhere else, you can run your pages through
www.copyscape.com
That site will help give you a basic idea how googles algorithm is finding duplicated content on your site that they deem NOT original.
The days of Copy / Paste, RSS feeds, Article sharing, etc.. content driven sites are Over... Now days, you need to at least write 25% to 50% of the content yourself so that it can pass googles originality tests.
As others mentioned though, it's best to go directly to google and ask them what to do about your content situation. My suggestions above are just a basic tip of the iceberg, There's much more you should know.
Good luck to you,
Eric Lyon