In the trend of global economic integration, the competitiveness of Chinese enterprises' products is be impacted and the choice of development strategy of Chinese enterprises is particularly important in the trade framework of WTO. In the Cournot-Nash framework, this paper studies the brand collaboration in the condition of international trade. The research shows that a firm owning a superior brand only collaborates with a less reputed firm provided that it has already established its reputation to some extent. The paper also argues that the tariff on affects the conditions of the collaboration.