Mathematical representation ability is one of the important components in an effort to develop students’ thinking ability. However, in TIMSS’ report, it said that students’ ability in representing idea or concept is still low. One of the alternative ways to use is IMPROVE method in mathematics learning. Based on the problem, this study will compare the mathematical representation ability between students who take mathematics learning with IMPROVE method and students who take mathematics learning with conventional method. This study applied quasi-experimental method with Nonequivalent Control Group Pretest-posttest Design. Based on the results and discussions of this study, it can be concluded that the mathematical representation ability of students who learn mathematics with IMPROVE method is better than students who take mathematics learning with conventional method.