Google increased its share of the market during the second half of 2009 to 43% vs. Baidu's 56%, according to web analytics company StatCounter.
"Google has made impressive gains in China since July last when it was at 30% compared to Baidu's 68%," said Aodhan Cullen, CEO of StatCounter, in a statement. "Our analysis suggests that given Google's recent strong performance, market share is certainly not the reason behind its threat to leave China at this time."
Google and Baidu are miles ahead of Yahoo and Bing in China's search market, as those two also-rans have combined for just 1.18%, according to StatCounter.
Google's global share is over 90%, according to StatCounter.
Google said this week it will stop censoring search results in China, a decision that follows an attack on Google's servers in December that targeted the Gmail accounts of Chinese human rights activists.
IDG News Service contributed to this report.