This study applies the Problem Based Learning Model to improve the learning outcomes of science in the material Benefits of Diversity and Preserving Cultural Diversity in class IV SDN Bangunharjo. This study is a classroom action research with two cycles, consisting of one meeting each cycle and four stages: planning, implementation, observation, and reflection. The subjects of the study were 27 students of Class IV SDN Bangunharjo in the 2023/2024 Academic Year, with 15 male students and 12 female students. Data collection techniques include observation, interviews, tests, and documentation, and data analysis using qualitative descriptive methods. The results of this study aim to improve the learning outcomes of science in the material Benefits of Diversity and Preserving Cultural Diversity. This is evident from the initial condition of the percentage of student completion of 37.03% (10 out of 27 students completed learning) with an average class score of 62.22. In cycle I, the percentage of student completion was 62.96% (17 out of 27 students completed learning) with an average class score of 69.62. Meanwhile, in cycle II, the percentage of completion increased to 88.88% (24 out of 27 students completed learning) with a class average score of 77.03. Based on the results of this study, it can be concluded that the application of the Problem Based Learning learning model can improve the learning outcomes of Science in Class IV students of SDN Bangunharjo in the 2023/2024 Academic Year.