Penelitian ini merupakan kuasi eksperimen berbentuk kelompok kontrol pretes-postes, dengan perlakuan pendekatan pembelajaran Think-Talk-Write (TTW) dan pembelajaran konvensional. Berdasarkan hasil analisis data, diperoleh kesimpulan bahwa peningkatan kemampuan komunikasi matematik siswa yang memperoleh pembelajaran dengan kooperatif Think-Talk-Write (TTW) lebih baik daripada siswa yang memperoleh pembelajaran dengan cara konvensional.   Kata kunci : komunikasi matematik,  Think-Talk-Write (TTW)     This research is a form of quasi-experimental pretest-posttest in controlling group, which is using both of the cooperative learning approach of Think-Talk-Write (TTW) and the conventional learning. Based on the results of data analysis, it is concluded that the improvement of mathematical communication abilities of students who received cooperative learning with Think-Talk-Write (TTW) is better than the students who received the conventional learning.   Keywords: mathematical communication, Think-Talk-Write (TTW)