With the development of new media,the media ecology in China has undergone tremendous changes.At the same time,social public opinion research under new media environment has also become a distinguished school.However,researches in the relevant field are still mainly on case studies and speculative researches,diachronic studies based on a large sample database are very lack.Considering this,relying on strong technical background,Public opinion research laboratory of Shanghai Jiaotong University explores to do a empirical research on change law of social public opinion events from 2007 to 2011years,with the help of information,data mining technology and in the diachronic perspective,which will research several key elements mainly such as the communication media,opinion leaders,rumors,the network mobilization,and public policy,in order to find out some intrinsic characteristics and provide public opinion subjects scientific reference for management,decision making,and public opinion response. <<