Abstract: The continuous variable linear programming model or the mixed integer programming model is usually established to solve the problem of fleet planning. But the results of those models sometimes lead one ship runs several routes. From the aim of safety and management，the transport model which one ship only runs one route is required and the integer programming model is needed to solve the problem. In this paper，the continuous variable linear programming model and the mixed integer programming model were established based on the problem of formation of the fleet. And the integer programming models were also studied. The characteristics and scope of four optimization models were discussed by an example.