This article intends to discuss the relationship among the public security, the economic efficiency and the social capital. It has pointed out that the public security is helpful to improve the economic efficiency and achieve the economic growth, but economic growth does not necessarily ensure social public security. A large investment of security personnel and security facilities without consideration for cost does not really solve the social security problems. It is only able to transform the dominant security problem into the recessive security problem. Finally, the substantive public security has not been improved. Thus, it is impossible to bring about the absolute security. However, the formation and accumulation of social capital will enhance substantive public security. Additionally, Much attention should be paid to the development of citizen association and organization, which effects the positive social capital accumulation, especially to focus on family-building role of social capital formation.