Recent curriculum innovations encourage teachers to demonstrate their professional wisdom by participating in school-based curriculum development (SBCD). As we know, the devolution of central curriculum policy doesn't mean that teachers can conduct SBCD effectively. In Taiwan, there are few studies systematically to respond to the critics about SBCD. In order to gain a comprehensive understanding of the nature and problems of SBCD, this study investigates the context of SBCD based on 6 subsystems-external environment, curriculum, staff, school structure, resources, and evaluation. This study proposes several paradoxes founded in SBCD by analyzing the empirical survey data. Finally, it provides some implications for future curriculum practice and research in SBCD.