ABSTRACT This study was motivated by the low level of self-control among students with Autism Spectrum Disorder (ASD), particularly in relation to leaving their seats during classroom learning activities. This behavior is categorized as off-task behavior and may disrupt both the learning concentration of other students and the overall teaching process. The study aimed to examine the effectiveness of a reward chart-based token economy in improving self-control by reducing seat-leaving behavior among students with ASD. The research employed a Single Subject Research (SSR) approach using a single-subject experimental design. The research procedures consisted of a baseline phase to identify the frequency of the target behavior, an intervention phase involving the implementation of a reward chart-based token economy, and a measurement phase to evaluate behavioral changes following the intervention. Tokens were provided as positive reinforcement whenever the student successfully remained seated according to the predetermined target. The collected tokens were placed on a reward chart and could later be exchanged for rewards based on the student’s preferences. The findings indicated that the implementation of the reward chart-based token economy effectively improved self-control, as evidenced by a gradual decrease in the frequency of seat-leaving behavior during the intervention period. Therefore, a reward chart-based token economy can be considered an effective behavior modification strategy for reducing seat-leaving behavior and promoting classroom engagement among students with ASD. ABSTRAK Penelitian ini dilatarbelakangi oleh rendahnya kemampuan kontrol diri pada siswa Autism Spectrum Disorder (ASD), khususnya terkait perilaku meninggalkan tempat duduk selama proses pembelajaran di kelas. Perilaku tersebut termasuk off-task behavior yang dapat mengganggu konsentrasi belajar siswa lain dan menghambat efektivitas pembelajaran. Penelitian ini bertujuan untuk menguji efektivitas token ekonomi berbasis reward chart dalam meningkatkan kontrol diri siswa ASD melalui pengurangan perilaku meninggalkan tempat duduk. Penelitian menggunakan pendekatan Single Subject Research (SSR) dengan desain eksperimen subjek tunggal. Pelaksanaan penelitian meliputi tahap baseline untuk mengidentifikasi frekuensi perilaku target, tahap intervensi berupa penerapan token ekonomi berbasis reward chart, serta tahap pengukuran perubahan perilaku setelah intervensi diberikan. Token diberikan sebagai penguat positif setiap kali siswa berhasil mempertahankan posisi duduk sesuai target yang ditetapkan, kemudian token dikumpulkan pada reward chart dan dapat ditukarkan dengan hadiah yang sesuai dengan minat siswa. Hasil penelitian menunjukkan bahwa penerapan token ekonomi berbasis reward chart efektif meningkatkan kontrol diri siswa ASD yang ditunjukkan oleh penurunan frekuensi perilaku meninggalkan tempat duduk secara bertahap selama periode intervensi. Dengan demikian, token ekonomi berbasis reward chart dapat menjadi strategi modifikasi perilaku yang efektif untuk mengurangi perilaku meninggalkan tempat duduk dan mendukung keterlibatan siswa ASD dalam proses pembelajaran di kelas.