With the development of Internet technology, the analysis of net-mediated public opinion based on text mining, has become increasingly concerned by the academic community in recent years. In this paper, we do research on net-mediated public opinion of China\u27s real estate in the second quarter of 2015empirically with the association rules, text tendency analysis and other technology of data mining and visualization. On the basis of the demonstration, a basic framework of net-mediated public opinion analysis is constructed. According to the analysis of this paper, the distribution and association of hot topics in this quarter were found, and the overall tendencies of the topics were reviewed, also some relevant policy recommendations were given