This study aimed to improve the learning process and improve the student’s Mathematical Problem Solving Skill (MPSS) by applied Problem Based Learning (PBL) model. This study was Classroom Action Research with two cycles. This research conducted of class VIIIA2 MTs Darul Hikmah Pekanbaru on first semester of academic year 2018/2019 wich consists of 28 female students with heterogeneous acade…