为探究海上集装箱运输链中上游港口默契合谋与下游船公司的行动时机和策略变量类型双重内生选择的影响关系，在无限重复次博弈中分析下游船公司不同竞争模式下上游港口默契合谋的动机以及稳定性，并据此求解船公司内生行动时机和竞争类型均衡.结果表明：港口合谋在船公司同时行动的运量竞争中最易维持，而在同时行动的伯川德-古诺混合竞争下最难维持；船公司的双重内生选择与运输服务替代性及港口折现因子有关，均衡策略为同时行动或序贯行动的运量竞争、同时行动或以运量竞争主导的混合竞争.本文研究也可为发展改革及运输部门加强对港口默契合谋的鉴别提供依据.

In order to explore the effects of the tacit collusion of upstream ports on the carriers' endogenous timing and competition strategic variables in the maritime
In order to explore the effects of the tacit collusion of upstream ports on the carriers’ endogenous timing and competition strategic variables in the maritime container transportation chain, the motivation and stability of the tacit collusion of upstream ports under different competition mode of downstream shipping companies were analyzed in infinitely repeated games. Furthermore, the dual endogenous choices equilibrium of the shipping companies’ endogenous timing and strategic variables was solved. The results show that port collusion is the easiest to sustain under simultaneous quantity competition of shipping companies, but the most difficult to maintain under the BertrandCournot mixed competition where the shipping companies act at the same time. The shipping companies’ dual endogenous choices are not only related to the substitution of transportation services but also to the port discount factor. In equilibrium, carriers can engage in quantity competition with three kinds of move time modes, mixed competition of simultaneous actions, and the mixed competition where the liner competes in quantity as the leader while another chooses price as the follower. The research in this article can also provide a basis for the development and reform and transportation departments to strengthen the identification of ports tacit collusion.