The research focused on the influence of STAD tostudents' activityand students' physics achievement. The purposesof this research are (1) toexamine the effect Student Teams Achievement Division model to students'physics achievement in learning physics, (2)to describe students' activityusing Student Teams Achievement Division model in learning physic. Thetype of this research is experiment by using post-test only control design.Sample of the research are X MIPA 3 as an experiment class and X MIPA 4as an control class.The techniques of data collection are observation,test,documentation, interview andportofolio. The techniques of data analysisusing descriptive analysis and Independent Sample T-Test by SPSSversion16. The result of the research are (1) students' physicsachievementacquiredof analytical results Independent-Sample T-test Sig. (1-tailed) of 0, (2)average value students' science process skills is 89,91. Theresearch can be concluded that (1) there are effect of problem basedlearning model to students' achievement in learning physics, (2) the studentactivity isin good criteria.