In the third quarter of last year, Baidu had 78.6 percent of the Chinese search market, while Google had 15.4 percent, in terms of revenue, according to domestic research company Analysys International.
Google reached its peak in China in the fourth quarter of 2009, when it had 35.9 percent of the market. But the gap between Baidu and Google has been narrowing since then, especially after Google shut down its search engine operations on the mainland and started redirecting users to a Hong Kong-based search website in 2010.
Faced with a declining market share in China, Google is pushing into the mobile sector, trying to generate revenues from its mobile advertising products, which enable ads to be shown on mobile applications, mobile search results and online videos.
John Liu, corporate vice-president of Google China, said earlier the mobile ad business is the company's fastest-growing business in the country.
Mobile ad requests via Google's products increased 120 percent from July 2011 to July 2012 in China. The country is one of Google's top-five global markets in terms of ad request volume.