Abstract: Retailer collusion is a method for improving profit; it will influence the decision-making conduct of channel pricing. Aiming at the conventional channel structure made by many manufacturers and retailers, the influence of retailer collusion on channel pricing decision under three kinds of channel power structure is discussed. The research results are as follows. Regardless of power structure, retailer differentiation has no impact on the channel pricing decision. When the production cost is above the certain value, the trade price and retailing pricing under retailer collusion are higher than that under non-retailer collusion. Retailer collusion will be of benefit to the retailer, but do the damage to the manufactures. When the production cost is higher than the certain value, no matter which channel member is in the position of Stackelberg leader, consumers will gain the benifit. Under a power structure, the profit levels for the manufacturer and retailer are the highest. Under whichever power structure, if there is collusion between retailers, and the product differentiation is larger, the manufacturer will be better off and will have a negative effect on the retailers.