This paper deals with optimal decision methods under a cooperative situation of the two-echelon model among logistic service providers (LSPs) of Stackelberg structure. Assuming duopolistic shippers and oligopolistic forwarders, the shippers perform as a leader and declare their service to both the forwarders after determining their price and quantity independently under shippers' scheme. The objective of this study is to obtain the optimal strategies of exporters in the three types of rival game behaviours: Stackelberg, Collusion and Cournot, each of which provides the optimal decision for the duopolistic shippers and the oligopolistic forwarders in each scenario. The result of a real situation indicates that: (i) among three scenarios, the oligopolistic treatment of forwarders' actions shows that Stackelberg behaviour can carry out the maximum profit, and (ii) Collusion game can achieve the maximum profit for the shippers.