Researches have revealed the deep impact of class environment on student learning outcomes and proposed a serial of methods for survey and taxonomy. But these efforts suffer from two issues: (1) They emphasize the holistic measurement and evaluation of class environment, but ignore the individual effects in the class. (2) They do not consider interpersonal behaviors among the students and teachers. In this paper, we address these two challenges as follows. First, we introduce a half anonymous survey instrument to assist individual opinion data collection. Second, we adopt social network analysis to explore relationships among students. An empirical class test was conducted to verify the method. Experimental results have demonstrated the ability of our approach to discover the class environment problems with high reliability and veracity.