. The purpose of this research is to improve the mathematics learning outcomes of the fourth grade elementary school students the material of the Roman numerals for the fourth grade students of semester 2 of SDN Sumur 03 of 2016/2017 through the Role Playing learning model. This research is a classroom action research (CAR) which consists of 3 cycles. Each cycle consists of four stages, namely (1) Planning (2) Action, (3) Observation (4) Reflection. This research was conducted for 4 months, from February to May 2017 which was held at Sumur 03 Elementary School, Cluwak District, Pati Regency. The subjects of this study were fourth grade students in semester 2 of 2016/2017 consisting of 13 students. Data collection method through observation, documentation and test methods. The data analysis technique used was descriptive comparative by comparing the results of pre-cycle mathematics learning with the results of mathematics learning after the cycle. Conclusion the results of the study are after conducting classroom action research through the Role Playing learning model, the learning outcomes of Mathematics subject matter Roman numerals for fourth grade students in semester 2 of SDN Sumur 03 experienced an increase both theoretically and empirically.