Problem Based Learning (PBL) is a problem-based learning model that can help students understand the subject matter and help improve students' problem solving abilities. This study aims to determine the effect of the problem based learning (PBL) model on students' problem solving abilities on the material of the reproductive system. This type of research is pre-experimental with One-Group Pretest-Posttest design. The sampling technique is non-probability sampling with total sampling. The research sample was 39 students of class XI. The data collection technique used pretest and posttest instruments, the data analysis technique used was the One-Sample Kolmogorov-Smirnov Test with an average pretest result of 23.08 with a significance of 0.00, the posttest average showed a value of 85.18 with a significance of 0. 03, and the average N-Gain shows a value of 0.81 with a significance of 0.01 as evidenced by statistical analysis which states that the data significance is < of = 0.05, thus there is an effect of Problem Based Learning Learning Model on Student Problem Solving Ability, then the conclusion of this study is Ho is rejected and Ha is accepted. Keywords: problem-based learning, problem-solving