Abstrak:Tujuan penelitian ini adalah untuk mendeskripsikan kemampuan komunikasi matematis ditinjau dari keterlibatan siswa pada materi segiempat melalui pendekatan RME. Penelitian ini merupakan penelitian kualitatif. Subjek dalam penelitian ini adalah 6 orang siswa kelas VII-1 SMP IT AL-Azhar Banda Aceh yang dipilih berdasarkan banyaknya indikator keterlibatan yang dipenuhi. Teknik pengumpulan data yang digunakan dalam penelitian ini yaitu observasi keterlibatan siswa dan tes kemampuan komunikasi matematis yang telah divalidasi. Data dianalisis dengan melakukan reduksi data, penyajian data dan penarikan kesimpulan. Berdasarkan hasil penelitian maka dapat disimpulkan bahwa kemampuan komunikasi matematis ditinjau dari keterlibatan siswa melalui pendekatan RME sudah baik. Hal ini terlihat dari hasil pencapaian kemampuan komunikasi matematis yang ditinjau dari keterlibatan siswa terhadap 4 orang subjek sudah berada pada katagori baik, artinya subjek telah memperoleh pembelajaran dengan baik karena pada saat pembelajaran subjek terlibat aktif serta memiliki kemampuan komunikasi matematis yang baik. Penggunaan pendekatan RME juga membangkitkan semangat siswa agar terlibat dalam pembelajaran serta memperoleh kemampuan komunikasi matematis yang baik. Namun, terdapat dua subjek dengan keterlibatan serta kemampuan komunikasi matematis dalam pembelajaran yang masih rendah. Kata Kunci:                        Kemampuan Komunikasi Matematis, Keterlibatan Siswa, Pendekatan RME Abstract:The purpose of this research was to describe students' mathematical communication skills. They were observed based on students’ involvement in studying quadrilateral through the Realistic Mathematics Education (RME). This research was a qualitative research. The subjects in this research were 6 students of class VII-1 Islamic Junior High School AL-Azhar Banda Aceh who were selected based on the number of certain indicators that were fulfilled. The data collection techniques used in this research were observation of students’ involvement, and tests of mathematical communication skills. The instruments for data collection had been previously validated. The data were analyzed by doing data reduction, data presentation, and drawing conclusions. Based on the research results, it could be concluded that students' mathematical communication skills observed based on students’ involvement in the learning quadrilateral through the RME approach were good. This could be seen from the achievement of 4 students who accomplished good chategory in mathematical communication skills. This showed that the subjects had learned well because at the time of learning, the students actively involved and accomplished good mathematical communication skills. Thus, the use of the RME approach also aroused students' enthusiasm to be involved in learning and acquired good mathematical communication skills. However, there were still two subjects with low involvement and mathematical communication skills. Keywords:Mathematical Communication Skills, Students’ Involvement, RME Approach