A survey by London-based researcher GlobalWebIndex found Facebook had 63.5 million users in the second quarter of this year, compared with 7.9 million in mid-2009.
Twitter had 35.5 million users at the end of June – triple the number it had three years ago.
The data is based on responses to online surveys in Mandarin.
“It only takes a little bit of desk research to discover that what is called the ‘Great Firewall’ is actually much more porous than the Chinese government would like to admit,” said Tom Smith, founder of GlobalWebIndex.
Internet users in China access banned websites via virtual proxy networks, which connects them to servers outside the country and enables them to evade Beijing’s army of censors.
The Chinese government blocks access to foreign websites and content that it considers politically sensitive or inappropriate.
Despite their fast growth in China, Facebook and Twitter hold only a relatively small share of the world’s largest Internet market of more than half a billion users, Bloomberg reported.
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