The aims of this study is that to describe the effectiveness of physics module developed using cooperative learning model with peer assesement. The teaching materials physics examined in chapter circular motion. This type of study is quantitative description with pre experimental design. The subject of this study is class XB SMA Muhammadiyah 1 Banjarmasin. Data were collected achievement test. The data analysis technique is descriptive quantitative analysis. The results showed that the physics module class X using cooperative learning with peer assessment is effective in term of student learning outcomes. Keywords: Effectiveness, physics module, cooperative, peer assement.