Development is a permanent issue in school worldwide which teacher demand in enhance their competence, especially in professionalism competence. The main purpose of this article is to investigate whether three factors were influence teacher professionalism development, those are (1) leadership of principal, (2) organizational commitment, (3) school culture. This research is survey research. The population was 182 teachers of Muhammadiyah Secondary School of Yogyakarta. A sample of 162 teacherswasestablishedusingthesimplerandomsamplingtechnique.Thedatawere collected through questionnaire that had been tested for validity and reliability. The data analysis technique used double regression. The research finding shows that there was a positive and significant effect of: (1) leadership of principal on teacher professionalism development, as much 15,7%, (2) organizational commitment on teacher professionalism development, as much 15,7%, (3) school culture on teacher professionalism development, as much 21,1%.
Factors Influencing Teacher Professionalism Development on Secondary School