Penelitian ini bertujuan untuk mendeskripsikan kemampuan komunikasi matematis siswa SMP pada materi himpunan. Jenis penelitian ini adalah penelitian kualitatif dengan metode deskriptif. Populasi pada penelitian ini adalah siswa kelas VIII SMP Swasta Al Manar. Peneliti mengambil subjek sebanyak 6 siswa, yang dipilih masing-masing 2 siswa dari setiap kategori kemampuan komunikasi matematis tinggi, sedang, dan rendah. Hasil penelitian ini adalah 1)terdapat satu orang dari kategori kemampuan komunikasi rendah yang kurang tepat dalam menyelesaikan persoalan terkait himpunan, 2)terdapat siswa dengan kategori kemampuan komunikasi rendah belum mampu menyatakan anggota-anggota himpunan secara tertulis, 3)terdapat siswa dengan kategori sedang dan rendah mengalami kesulitan dalam menyajikan himpunan dalam bentuk notasi, serta dalam pengoperasian himpunan. ABSTARACT This research aims to describe the mathematical communication abilities of junior high school students on set material. This type of research is a qualitative research with descriptive method. The population in this study was class VIII students at Al Manar Private Junior High School. The researchers took as many as 6 students as subjects, each of which was 2 students from each category of high, medium, and low mathematical communication skills. The results of this study were 1)there was one person from the low communication ability category who was not quite right in solving problems related to the set, 2)there were students with the low communication ability category who had not been able to state the members of the set in writing, 3)there were students in the medium category and have difficulty in presenting the set in the form of notation, as well as in the operation of the set.