This research aims to improve fifth grader students’ score in Mathematics subject at SDN Tebaloan, Duduk Sampeyan, Gresik Academic Year 2016-2017 using Realistic Mathematics Education improve.

This research is a Classroom Action Research (CAR). This research uses Kemmis and McTaggart model. The research is conducted in two cycles. Evey cycle consists of four stages; planning, action, observation and reflection. The data are obtained from students’ score of tests, observation result during the teaching-learning activities using observation sheet of the teacher’s activity in implementing Realistic Mathematics Education, observation sheet of  students activity and documentation. The data analysis technique is using data collection technique done through tests (formative) and non-tess (observation and documentation). The indicator of successfulness in this research is that average score  is better than 65, percentage of total classical learning is more than 70%, students’participation in classroom activities is higher than 70% and teacher’s performance score exceeds 70%. The result of this research shows the improvement of students’ score, students’ participation and teacher’s performance from cycle I to cycle II. During the cycle I, the students’ average score is 68.75%, the percentage of total classical learning achieve 64.70%. Meanwhile, in cycle II, the average becomes 76,37% and the percentage of total classical learning gets 88.23%. Based on the result, it can be concluded that Realistic Mathematics Education can improve fifth graders students’ score  at SDN Tebaloan, Duduk Sampeyan, Gresik. Therefore, Realistic Mathematics Education can be an alternative approach in teaching to improve the quality of teaching at schools.