Abstract: Based on information asymmetry,a model of pursuing private benefits of control was presented to study restraining role of potential risks. The main conclusions of the paper are as follows. First,controlling shareholder will choose a level within given interval,namely private benefits tolerance interval to compensate benefits for controlling cost and to maintain the sustainability of the benefits with restriction of potential risks. Second,rational private benefit of control will not only inspire controlling shareholder,but also protect the interests of minority shareholders and corporation value. Third,excessive private benefits of control have the nature of infringement on minority shareholders,which will reduce the benifit of minority shareholders and the value of corporation. Finally,an explanation about paradox of private benefits of control is presented,some conclusions and suggestions based on the theoretical analysis are given.

Key words: control shareholder, information asymmetric, potential risks, rational private, benefits, excessive private benefits