This study aims to determine whether there are differences in the increase in mathematical connection skills of students who are given the application of outdoor learning with media clinometers with conventional learning. This research is a quasi-experimental research (Quasy Experimental Design). This study uses independent variables, namely outdoor learning with clinometer media with symbol (X) and the dependent variable is the students' mathematical connection ability with a symbol (Y). This study used a pretest and posttest-only control design. The instrument used in this study is a test that is used to determine the completeness of student learning outcomes and students' mathematical connection skills. Data collection was done with questions about the pretest and posttest in the control class and experiment. The hypothesis testing of the researcher uses the t-test. Based on the research results it can be concluded that there are differences in the increase in mathematical connection ability of students given the application of outdoor learning with media clinometers with conventional learning and from the results of N-gain data processing it can be concluded that students' mathematical connection ability with outdoor learning with clinometer media is better than learning conventional.