This paper investigates a supply chain in which a retailer is supplied by two manufacturers with differentiated brands, a good brand and an average brand. According to the power structure differences, and considering the environment factors such as brand differentiation, two types multiple-stage game models are constructed, which are the Stackelberg game models dominated by the retailer and manufacturers respectively. By the solutions, we derive, for each manufacturer, the optimal pricing of the system under each power structure. Further, we analyze the effects of the environment factors on the equilibriums, and consequently compare the system profits under different power structures companied with numerical examples. The results show that, different power structures will not affect retailers' optimal pricing and demand. Different from the retailer's dominance, leads to the higher profit for the good brand manufacturer and the lower for the average brand manufacturer or retailer under the manufacturers' dominance. Moreover, no dominance among supply chain members (the two manufacturers and the retailer) leads to the highest profit for the entire supply chain and consumer surplus.