Abstract: The professionalization of lawyers follows closely the construction pace of China’s legal system，and is continuously developing under the influence of the legal community concept. The practice of public welfare protection in the transitional society has gradually given birth to a new group of lawyers. Public welfare defense lawyers actively intervene in disputes of social interests， enhance public welfare protection，and satisfy the demands of individual rights or group interests；then they need policy optimization and even institutional reform，which has a conspicuous professional nature. In the practice of public welfare protection，by“extending”the legal issues of a specific case，public welfare lawyers use the case to influence public opinion，thus turning the case into an event. After successfully obtaining“the concern of stability maintenance，”they should turn the event back into a case，activate institutional resources，and re-legalize the public welfare case，so that it can finally be properly handled within the institutionalized channels. Grasping the action strategies in the process of public welfare protection，highlighting the goals and directions of public welfare protection practice，and expanding the institutional reform effect of public welfare protection，it is conducive to enhancing the group cohesion and professional integration of public welfare lawyers，and finally realizing the institutionalization of the emerging legal profession of public welfare protection.

Key words: public welfare defense, lawyer, professionalism, process-event analysis, institutionalization