Sekarang ini banyak masalah yang ditimbulkan karena kurangnya penerapan disiplin sejak masa anak-anak. Berdasarkan pengamatan di sebuah taman kanak-kanak (TK), peneliti menemukan banyak siswa TK yang tidak bersikap disiplin. Banyak siswa tidak mau mendengarkan guru selama pelajaran. Siswa sibuk memukul, menendang, dan mengejek teman. Siswa tidak mengangkat tangan ketika ingin berbicara. Tujuan penelitian ini adalah a) mengetahui penerapan reward dapat meningkatkan disiplin terhadap peraturan kelas dan b) menjelaskan langkah-langkah efektif penerapan reward untuk meningkatkan disiplin terhadap peraturan kelas siswa TK-B. Metode penelitian yang digunakan adalah metode Penelitian Tindakan Kelas dengan model Kemmis dan McTaggart. Subjek Penelitian yang akan diteliti yaitu siswa Taman Kanak-kanak yang berusia 5-6 tahun berjumlah delapan siswa. Penelitian akan bertempat di sekolah dasar swasta di Papua dan dilakukan sejak 25 September 2015 hingga 30 September 2015. Penelitian ini berlangsung selama dua siklus. Instrumen yang digunakan adalah lembar observasi guru mentor, wawancara guru mentor, angket siswa, dokumentasi reward chart, dan lembar refleksi peneliti. Proses analisis pada penelitian ini menggunakan teknik analisis deskriptif kualitatif. Berdasarkan hasil analisis, peneliti menyimpulkan bahwa penggunaan penerapan reward dapat meningkatkan disiplin siswa TK-B. Hal ini dibuktikan dari hasil analisis pengamatan dari siklus pertama dan kedua, diketahui adanya peningkatan jumlah siswa disiplin yaitu sebesar 75% dari jumlah siswa di dalam kelas dengan kriteria ≥ baik (3,4) dan telah memenuhi indikator-indikator yang telah peneliti tentukan./There are many problems happened because of lack of discipline for children these days. Based on the observation in a kindergarten school, researcher found that many kindergarten students showed indisciplinary behavior. Most of the students did not want to listen to the teacher during the lesson. They were busy hitting, kicking, and teasing others. Students did not raise their hands when they wanted to talk. The purposes of this research are to know implementation of reward to increase kindergarten-3 students’ discipline to toward classroom rules in xyz school and explain the effective steps for implementation of reward to increase kindergarten-3 students’ discipline to toward classroom rules in xyz school. Research method that the researcher used is Classroom Action Research (CAR) with Kemmis and McTaggart model. Subject of this research is 8 kindergarten students (5-6 years old). This researcher is taken place in a private elementary school in Papua from September 25th until September 30th 2015. The researcher conducted 2 (two) cycles. The instruments for this research are mentor observation, mentor interview, students’ questionnaire, reward chart documentation, and researcher’s reflection. The analysis process of this research is qualitative descriptive analysis. Based on the analysis results, the researcher conclude that the application of reward is able to increase kindergarten-3 students’ discipline. This conclusion is showed by the observation analysis from first cycle and second cycle, there is an increasing percentage of the students (75%) from the total number of students with criteria ≥ good (3,4) and it is fulfilled the indicators that the researcher set in the beginning.