This study aims to analyze the success factors of the Taiwanese-Japanese joint venture in China by using the concept of co-innovation. To that end, first, the Co-innovation Theory is defined and drawn from the related literature concerning the international joint venture (IJV), strategic alliance and strategic networks between global enterprises. Based on the well-defined Co-innovation Theory, eight enterprises are studied and analyzed for their development style of the co-innovation. The conclusions drawn from our analysis of Taiwanese-Japanese co-innovation in China are as follows: First, based on our research, the co-innovation network development demonstrates various styles which include Basic Type, In-Depth Type, Extended Type, and In-Depth Extended Type. Second, the Taiwanese-Japanese co-innovation in China meets the changing environment to well utilize capital structure flexibly, uses functional organization advantage of each other, and shares China information effectively. Contrary to previous studies, co-innovation is based on (1) reliable relationship, (2) invisible cooperation by sharing information, (3) a clear division of management functions between partners, and (4) utilization of competitive advantage each other. These aspects form the success factors of the Taiwanese-Japanese joint venture in China. Third, the Taiwanese-Japanese co-innovation in China has been established on either extended or in-depth co-innovation network development. At an in-depth co-innovation network co-innovation is built upon partners' mutual reliable relationships, whereas at an extended counterpart, Taiwanese partners dominate with their advantages. The vantage point of the Taiwanese enterprises comes from their understanding of the Chinese value and its ever-changing system. In addition, they have the capability of improving and modifying products, extending sales channels, and the ability of developing and managing Chinese local staff and local component suppliers. Fourth, the core meaning of co-innovation is to share the local information in order to adjust to China's uncertain and server-changeable operation environment. The co-innovation network results in the "invisible cooperation" among competitors. Utilizing the advantage of the Taiwanese-Japanese co-innovation strategy has become the most efficient investing strategy for overseas enterprises to venture in China.