China has 649 million people online, but they are drifting away from microblogging sites after a government crackdown on free speech.
China's online population was already the world's largest.
Of those counted in the government-backed China Internet Network Information Center's annual report released today, 557 million were using mobile devices.
The number of microblog users dropped in 2014 by 32 million to 249 million, a decline that shows the sites failed to recover from the 2013 crackdown that chilled discussion on China's Twitter-like sites.
Meanwhile, newer products -- especially the instant messaging service WeChat -- are rapidly gaining popularity.
The report also says the number of users of mobile instant message services grew 17.8 per cent to 508 million.
