The research on the effects of supply chains members’cooperative advertising and costs sharing behavior on dual channel coordination on condition that manufacturer opens online and retail channel at the same time is extended. Research results show that no matter what effect retailer’s promotion has on brand image, when manufacturer pays part of retailer’s advertising cost, the outcome of two members would be better than that in the decentralized channel, but worse than that in the centralized situation. In addition, if the retailer also pays part of manufacturer’s advertising cost, dual channel is fully coordinated. Both members gain more values when retailer’s promotion effect on brand image is not negative.