The Internet has recently become an important source of social support. People living with HIV/AIDS (PLWHA) in China created an online support group (the HIV/AIDS Weibo Group) on Weibo, the Chinese equivalent of Twitter, in January 2011. To investigate social support in the HIV/AIDS Weibo Group, the content of all 7215 messages posted in this Weibo group since its launch on 18 January 2011, was analyzed. The analysis demonstrates that the majority of messages fell into the category of social support. Moreover, social support provisions were far more frequent than social support requests. The results also show that informational support, compared with emotional and instrumental support, was the most frequently requested and provided type of support in this Weibo group.