This research is aims to determine student learning independence in the application of project based learning in the Mathematics Education Scientific Work course in terms of the 21CLD self-regulation rubric. The research subjects in this study were students of the sixth semester of the Mathematics Education Study Program at Sultan Ageng Tirtayasa University who contracted Mathematics Education Scientific Work course as many as 25people, who would be categorized into students with high, medium, and low learning independence. The results after the interview process showed that research subjects whose learning independence was above the average score and had the highest score for statements in the questionnaire that met the 21CLD self-regulation rubric had good learning independence in the application of project based learning and students were able to self-regulate well in achieving learning objectives.Abstrak: Penelitian ini bertujuan untuk mengetahui kemandirian belajar mahasiswa dalam penerapan project based learning pada mata kuliah Karya Ilmiah Pendidikan Matematika yang ditinjau dari rubrik self-regulation 21CLD. Subjek dalam penelitian ini adalah mahasiswa Program Studi Pendidikan Matematika Universitas Sultan Ageng Tirtayasa semester enam yang mengontrak mata kuliah Karya Ilmiah Pendidikan Matematika sebanyak 25 orang, yang akan dikategorikan menjadi mahasiswa dengan kemandirian belajar tinggi, sedang, dan rendah. Hasil penelitian setelah proses wawancara menunjukkan bahwa subjek penelitian yang kemandirian belajarnya di atas nilai rata-rata dan memiliki skor tertinggi untuk pernyataan dalam angket yang memenuhi rubrik self-regulation 21CLD memiliki kemandirian belajar yang baik dalam penerapan project based learning, serta mahasiswa dapat mengatur diri sendiri (self-regulation) dengan baik dalam mencapai tujuan pembelajaran.