A telephone survey was conducted in a metropolitan city in 2012 to examine people’s credibility ratings of different media outlets, in particular, Weibo – one of the most popular social media platforms in China. Our findings suggest: First, people place more trust in traditional news media than in online sources by a significant margin. Second, demographic influences on media trust seem to be minimal. Only age and gender were related to some credibility measures. Third, Weibo use was not related to one’s credibility perception toward traditional media but interestingly, Weibo use showed different impacts on people’s evaluation of Weibo’s credibility. Commenting frequency was negatively related to one’s trust in Weibo, while retweeting frequency was positively related to one’s trust in Weibo.