Barriers to entry, which is the main factor determining market structure, has been a focus of industrial organization theory. From the angle of SCP literature to application of game theory, the scholars have not formed a common understanding of its exact definition. If uncertainty is brought into Market Entry Barrier Model, dynamic analysis of barriers to entry is a new way. After considering the factors such as adjust cost, time dependence and so on, the understanding of entry and barriers to entry is further deepened. The empirical studies which scholars at home and abroad conducted about relative industries also support this theory.