Due to the quasi-public attributes of medical service, the supply mode and system could influence equity and fairness of general people's health. Based on the view of public economics, the purpose of this paper was to explain the economic nature of medical service supply. By analyzing the practice of public-private partnership (PPP) mode in medical care supply and the related public economic issues, we summarized the feasibility and risks of PPP model in Chinese medical care supply market. Finally, we discussed the innovative medical service system provided by government, public hospitals, and social capitals together. Therefore, to guarantee further development of this new medical service supply--PPP mode, we should pay attention to some practical problems, such as the share of cooperation cost and the balance between the benefit and risk among all partners.