Pada kegiatan pembelajaran kelas IV di salah SD Kristen di Rantepao, ditemukan masalah sikap siswa yang belum maksimal dalam disiplin yang berdampak pada efektifitas belajar siswa. Tujuan dari penelitan ini, yaitu untuk mengetahui apakah penerapan peraturan kelas dapat meningkatkan kedisiplinan siswa dan untuk mengetahui langkah penerapan peraturan kelas yang dapat meningkatkan kedisiplinan siswa kelas IV di salah satu SD Kristen di Rantepao. Metode penelitian yang digunakan dalam penelitian ini model penelitan tindakan kelas yang dikembangkan oleh Pelton, yang dilakukan dalam dua kali penerapan pada tanggal 24 Oktober 2018 sampai 30 Oktober 2018. Subjek dalam penelitian ini adalah siswa kelas IV di salah satu SD Kristen di Rantepao yang berjumlah 28 orang. Hasil penelitian menunjukkan bahwa penerapan peraturan kelas dapat meningkatkan kedisiplinan siswa. Adapun langkah-langkah penerapannya adalah sebagai berikut: menerapkan peraturan, menerapkan konsekuensi, peraturan dikomunikasikan secara verbal dan tertulis kepada siswa dengan kalimat positif, menggunakan contoh konkret untuk mengilustrasikan peraturan, dan peraturan diingatkan secara berkala./ During teaching and learning activity in grade IV in one of Christian elementary schools in Rantepao, it was found an issue regarding students' behavior which had not yet been maximum in discipline which affected students' learning effectiveness. The purpose of this research is to know whether the implementation of classroom’s rules can improve students' discipline and to know the steps of classroom’s rules implementation which may improve students' discipline of grade IV in one of Christian elementary schools in Rantepao. The research methodology used in this research is classroom action research developed by Pelton, which was conducted in two implementations from October 24, 2018 until October 30, 2018. The subjects of this research were students of grade IV in one of Christian elementary schools in Rantepao which are 28 students. The research result shows that the implementation of classroom’s rules can improve students' discipline of grade IV in one of Christians schools in Rantepao. The implementation steps are as follows: set the rules, set the consequences, the number of rules is not more than five so will be remembered easily by the students, the rules are communicated verbally and in writing to the students with positive sentence, using concrete examples to ilustrate the rules, and the students are reminded periodically.