Selecting and implementing competitive strategies based on e-business is extremely important since it determines if an enterprise can continue to grow or not. Accordingly, systematic and empirical study on the implementation of e-business based on competitive strategy is required, and in-depth studies considering various e-business development stages of enterprises are also needed. The purpose of this study is to present guideline for the staff in charge and managers of enterprises to achieve competitive advantage and to increase organizational performance in e-business environments. What we have found are as follows. (1) Factors greatly influencing on competitive strategy selection through e-business were environmental uncertainty, centralization, innovative culture, technological competence, and formalization. (2) Results of the relationship between competitive strategies and e-business performance showed that each strategy had different effects on financial performance, process performance, and customer performance. and (3) Data analysis between internal and external environmental factors and competitive strategy by each e-business development stage proved that the relationships between competitive strategy and e-business performance were different based on e-business development stage. Implications of the study and guidelines for the managers are provided in the paper.