Abstract: The structure of Unbalanced-Bargaining-Power Supply Chain(UBPSC) is probably determined by comparison of bargaining powers between industries, influencing coordination and performance improvement in this supply chain. This paper on the definition of UBPSC models a two-tier one with upstream and downstream possessing asymmetric information respectively to attain game equilibriums. We further seek out some ideal prerequisites upon which system can achieve revenue increment optimally. However, there is no guarantee that these prerequisites can be readily fulfilled unless there are simultaneously certain incentives for both upstream and downstream. In order to obtain this outcome, this paper makes use of outside-force invention, instead of inter-force evolution to ensure the existence of those incentives, and also analyzes the conditions of this mechanism working under multi-period games circumstances.