Nearly 70% of China's internet users have a microblog account

"According to figures released today by the Data Center of the Chinese Internet (DCCI), nearly 70% of China's internet users have unique microblog accounts. 88.8% of Chinese internet users aged 19 or above have microblog accounts, and growth continues steadily."

Source:  Sina Tech, via Marbridge Daily, 26th July 2012

Note - while I've used 'Twitter' as a tag for the post, Sina Weibo is the most popular microblog in China.

More on Sina Weibo here