The aim’s of this research is to determine the increase in students' mathematical problem solving abilities using the discovery learning model. The research method used uses quasi-experimental techniques. The subjects of this research were 30 students at Kahuripan Lembang Middle School, class VIII-C. Data collection techniques through test questions and LKPD with discovery learning model stages. The data obtained was then analyzed quantitatively using the difference between two means test. The results of the research show that students' mathematical problem solving abilities use the discovery learning model for class VIII middle school because the learning activities carried out make students think more systematically, critically, creatively in solving the problems given, so that they can improve students' mathematical problem solving abilities.