The US$60 million acquisition marks the further expansion of the Shenzhen-based Tencent, already an Internet giant, following its US$300 million investment in a Russian social website earlier this year.
The Beijing-based Comsenz had been backed by a number of companies, including Google and Morningside Ventures.
According to Comsenz, its bulletin board system Discuz has been installed on over 1.4 million websites across the country. After the acquisition, Tencent aims to integrate its instant messaging service QQ with Disucz.
Comsenz's major rival, PHPWind, was acquired by Alibaba, another Internet giant in China.