This study tries to analyze the relationship between the internal competence and the competitive strategy of Korean corporations in China. And it also tries to find out the effects of suitability of the factors on their business performances. For this purpose, it surveyed 270 Korean corporations in China, and the results of the survey are as follows: First, when the effects of the internal competence on competitive strategy are investigated, it is proved that the technical competence and the marketing competence have a meaningful effect on differentiation strategy of Korean corporations in China. And the manufacturing competence has a meaningful effect on their cost leadership strategy. Secondly, in order to accomplish a high management performance, it is important for them to have suitable internal competence and management strategy. When they have high suitability, it has the biggest influence on their business performances. This results show that it is the most important for Korean corporations to establish a suitable competitive strategy for improving their performances, considering their internal competence.