Web surveys have become a very important way of empirical research. The rise of social media provides a new platform for web surveys. Investigators can collect data based on different social media platforms to get more respondents of higher external validity at a lower cost. However, there is no domestic expert and scholar to conduct related researches on web surveys based on social media. This paper studies the measurement equivalence of surveys among BBS, micro blog and SNS using CFA. The result shows that three surveys have the same basic structure, factor loading matrix and factor covariance matrix; moreover, the intercepts are equivalent across micro blog and SNS.