This study measured the post-entry expansion achieved by Japanese automotive parts manufacturers that entered the North American market in terms of the development of new buyer-supplier relations, and analyzed the factors determining such outcomes. The results of this study indicate that inter-firm experience in the home market, experience in the local market, and alliance strategies with local firms had significant influences. These findings suggest that while organizational capabilities accumulated through direct experience in the local market play an important role in achieving post-entry expansion in the host country, the development of such capabilities is also constrained by the firm's learning experiences in its home country. Furthermore, local alliance partners appear to help entering firms develop the capability to rapidly expand their business in the host country.