Abstract: With the explosive growth of information available on the Web, more and more users adopt search engines to collection information on the Internet. Meanwhile, sponsored search has become one of the most popular forms of Internet advertising because of its effectiveness and feasibility. As one of the predominant business model for Web search engines, sponsored search plays an important part in search engine studies. Sponsored search is popular among the small scale companies because it lowers risks and broadens market channels for these companies. But there remain many questions to be answered for sponsored search researches: Are sponsored results providing Web users good experience?Are Web search users disturbed by sponsored links on search engine result pages?How does sponsored search result affect the behavior of the search users?It is necessary to look into these questions and give advices to search engines and advertisers to make sponsored search more useful and acceptable. Click-through information is extracted from Web access logs collected by a commercial search engine in China. Based on analysis into this information, click through behavior on sponsored search results and ordinary results are compared. Experimental results show that some hypothesis proposed by previous researches dont accord with practical Web user behavior patterns. Meanwhile, a number of conclusions are also made to answer these proposed questions.