In order to solve the problems of inaction，slow action，disorderly action，and the problems of low public participation，low recognition，poor sense of acquisition in the long-term public security law enforcement service，Nanjing Public Security Bureau has explored and established the “Public Opinion Surveillance” mechanism in which the public opinion leading police service is the core. Moreover，the “good or bad evaluation” system of law enforcement service has also been established and improved，regarding the people as individual object of every law enforcement service. The practices above are innovative methods for the public to participate in security law enforcement and social governance，fully guaranteeing the public’s right to know，to participate，to express and to supervise，as well as effectively improving the capacity of the police and the credibility of law enforcement. As a result，a Nanjing Role Model of modernizing grassroots-level social governance is formed.