Many people trying to create adsense account fails to do the same. They often ask the reason, but forgets to read the Terms of Service while agreeing to it during sign up. There are many factors that are responsible for this. The age of URL is main among them. The minimum age should be atleast 6 months. Beside this you should have to take care of other factors. I am sharing here a URL that explains all the factors you should take care of before applying for new adsense account. Visit URL - http://googles-cash.blogspot.com/2009/04/know-why-adsense-is-rejecting-new.html