The purpose of the study was to develop activity-centered MST program through making solar cell car for the higher elementary school. The theme was chosen because 5-6th graders had been highly perceived and interested. As a development study it has taken both questionnaire and pilot/field tests. Basically, the study was performed following three stages. (1) Preparation stage: need anaylsis of MST program based on activity. (2) Development stage: developing design brief, teacher\'s guide, and students\' activity texts. (3) Improvement stage: establishing of validity and reliability of the MST program through pilot/field tests. In this study developed MST program has following characteristics: First, the program was developed to bring problem-solving ability and curiosity and interest about Mathematics, Scienece and Technology. Therefore it was capable of adapting properly in creative․discretionary activities, extra curriculum and regular class activities. Second, the program provided students with concerns about solar cell, one of future energy. It represented the process of constructing solar cell car through the design and problem-solving which is based on hands on activities. Third, for applying activity-centered MST progrm at classroom, it was consisted of sub-materials including design brief, teacher\'s guide, and students\' activity texts.