For the coordination control of production, transportation and inventory system in the presence of uncertainty in customer demands and lead time, from the point of optimizing logistics costs, the coordination model of transportation-inventory problem under the policy of direct shipping with truckload is established, and the effect of limited capacity of a railway truck on system decision is involved explicitly. A search procedure is advanced to solve the optimization cost model, and its superiority is also proved at mathematics. Finally, the numerical examples are presented to show that the capacity of a single truck can influence the optimal results.