The aim of this study was to analyze the effectiveness of learning materials through Problem Based Learning with Karo Culture Context (PBL-KCC), as well as improving students' mathematic problem solving ability and student self-efficacy. Learning materials developed were lesson plan, student book, student worksheet, mathematic problem solving ability test instrument and student selfefficacy questionnaire. This research is a development research using the development model of Thiagarajan 4-D model. Learning materials that have met valid criteria according to experts, were tested in class VII of SMP Negeri 2 Sibolangit. The results of the analysis of the data obtained indicate that learning materials based on PBL-KCC met the criteria of effectiveness and can improve mathematic problem solving ability and student self-efficacy. Based on the results of the study, it was suggested that mathematics teachers make an effort mathematic learning using learning materials based PBL-KCC.