This research is motivated by the lack of student learning outcomes in social studies in class IV SDN Lebo Sidoarjo. As much as 53% of students from 49 student learning outcomes in social studies are still under KKM is 70. Problem in this research is the student learning outcomes, teachers activity and student activity. Based on these problems, researchers finally implement problem based learning model. This study was designed using action research that consists of 3 cycle. Data collection techniques in this study is the observation, test, and field notes. The result showed an increased in each cycle. In the first cycle of student learning outcomes reached 43,2% with an average value of 65,5. In the second cycle of student learning outcomes reached 61% with an average value of 70. In the third cycle increased to 84,4% with an average value of 80,1. Based on these result it can be concluded that the application of problem based learning model to improve learning outcomes of students in social studies of class IV in SDN Lebo Sidoarjo.