This study aims to improve the mathematical communication skills of students in class VIII.A MTs Al Mujahdah Pagerandong Through Problem Based Learning with Think Pair and Share (TPS) Strategies. This type of research is Classroom Action Research (CAR). Classroom action research is carried out in 3 cycles with stages: (1) Planning, (2) Implementation, (3) Observation, (4) Evaluation, and (5) Reflection. Data collection techniques use observation sheets to observe the activities of teachers and students in teaching and learning activities and evaluation tests to measure mathematical communication skills. The data analysis technique is descriptive qualitative. The average test results of students during the learning process from cycle I to cycle II and cycle II to cycle III has increased. This shows that the test results of students' mathematical communication skills of each cycle also increased. The acquisition of the average value of each cycle is in the first cycle obtained 48.88 students in mathematical communication skills with less criteria, cycle II obtained 70.38 students have mathematical communication skills with sufficient criteria. While in cycle III it was obtained 77,62 students had mathematical communication skills with good criteria.