School-based curricula are seen as the important strategy to facilitate educational reforms and are spread in many countries, especially in Asia. However, the efficiency of developing and implementing school-based curricula in most schools are very low because the tasks those need to be dealt with are very complex and difficult. How to develop and apply the electronic performance support system (EPSS) to simplify the complexity and to improve the efficiency of school-based curriculum development and implementation becomes the important research and practical issue. In our prior work, a web-based computer-assisted instructional planning system, IPASS, was designed to provide a set of tools for individual teachers efficiently designing instructional plans. However, the system was dedicated for the design phase of curriculum development and did not support for all participants in different levels of school-based curriculum development, working on curriculum analysis, design, implementation and evaluation. This study designs and develops a novel web-based performance support system, SBCDSS, to assist the whole process of school-based curriculum development and implementation. The proposed system has been adopted in an elementary school in Taiwan and has received useful feedback regarding the usability and performance support for SBCD. Evaluation results and possible future work are discussed herein.