On the basis of asymmetric Information theory, it is seen that the underlying reason of the possibility of brand alliances is that the “information asymmetry” between consumers and producers, and the fact that consumer estimates the quality information of certain of the products by inferring unknown information based on brand alliances. A model of influential factors of brand alliances effects based on academic analysis of interrelated theory is proposed. It also is pointed that the crucial factor that influences the effect of brand alliance is the level of the difference between information consumer required and information market accommodated. This theory was also validated by the experimental means.