This study aims to propose some alternatives in architectural planning for reducing the class size of elementary, middle and high schools. In order to achieve above purpose, I discuss the current status of class size, the relationship between class size and educational outputs and the obstacles in realizing the optimum class size of elementary, middle and high schools during the past 40 years. Finally, the paper proposes 8 alternatives in reducing the class size, which can be considered during the early stage of school planning.