The public security of our country remains a stable development. The number of crimes decreased and the sense of safety of people has been strengthened. However，crime is an indication of social contradiction and conflicts. In different social development phases，various contradictions and problems affect the economic and social development at different levels. The paper analyzes the contradictions and problems in 2007，e.g. “indirect interest conflict”，“family slaughter”，“wealth hatred”，“social revenge”，etc. In the context of dramatic social change，the relevance between social psychological change and public security should become a new perspective on analyzing and understanding the public security issue.