This paper's goal is to develop the international trade model with the equilibrium constraints on maritime transport market in order to estimate the short-term economic impact of transition of port management policy. Especially, the present model explicitly concerns the effect of global alliances. First, we assume the oligopoly market, in which global carriers compete with vessel frequency in each OD market as well as the stochastic allocation on the shippers' route choice behavior. Thirdly, we bind these two sub-models to full model, which obtains the Nash equilibrium between global alliances. We apply this model to the actual international maritime transport market in 2000, and evaluate some scenarios of discounting the port charges.