China's leading web search company has launched an online, user-generated encyclopedia modelled on the US-based Wikipedia, which is blocked by Beijing.
More than 100 million people are online in China
The new service from Baidu.com, Baidupedia, is heavily self-censored to avoid offending the Chinese government.
Wikipedia had become increasingly popular in China until blocked in 2005.
China has strict laws on internet use and blocks content it deems a threat, including references to the Tiananmen Square massacre and notable dissidents.
The new Chinese service was launched last month.
Baidu's chief said the "initial reaction has been very positive", in an interview with the UK's Financial Times newspaper.
Robin Li told the paper his encyclopedia was modelled on Wikipedia, but said he was unaware Beijing had banned the Florida-based reference website.
Baidu has barred users from including any "malicious evaluation of the current national system", any "attack on government institutions" or "promotion of a dispirited or negative view of life", according to the paper.
Correspondents say the service highlights both the sensitivities of operating in the Chinese market and the opportunities for local companies by Beijing's blocks on thousands of overseas websites.
Last month Google unveiled its Chinese service with bullish forecasts and a robust defence of its decision to limit user access to certain internet sites.
Chief executive Eric Schmidt said that Google had no choice but to accept restrictions if it wanted access to China's internet market.
The number of internet users in China is set to top 187 million in two years.