Search engines are playing a more and more important role in discovering information on the web nowadays. Spam web pages, however, are employing various tricks to bamboozle search engines, therefore achieving undeserved ranks. In this paper, we propose a new page importance metric, which takes both the content quality and the link quality into consideration. Based on this metric, we can judge the trust scores of all the web pages using the web link graph. Experimental results running on over 15 million web pages show that our method can filter out spam and identify reputable sites effectively.