Abstract: This paper reviews the status of the researches on evolution of Internet public opinion, early warning mechanism and corresponding evaluation at home and abroad. It studies the basic problems of public opinion on the Internet, and introduces a variety of ways of evolution after the public opinion is produced. The characteristics of public opinion in five dimensions determine the emergence, development and evolution of public opinions. And it is not recommendable to regard action as the consequence of the public opinion on the Internet. It summarizes the theory and classification of the evolution law of the network public opinions, according to the themes, public opinion subjects, information dissemination and network behavior. For the early warning, natural language processing is the core technology but the index systems that cover public opinion themes, public opinion content, communication process, media and public opinion audience can be of different focuses wheras each system can be incomplete. For researches on solutions, they emphasizes specific ways rather than the systematic methods. Finally, the paper puts forward a series of specific research methods that addresses the issues of public opinion evolution on the Internet, its early warning and coping theory.

Key words: Internet public opinion, Evolution method, Early warning technology, Coping theory