AbstractBased on observations that researchers had done to teachers at SDN 19 Transverse Valley, it was found that the low level of professionalism of teachers in teacher performance. The purpose of this study is to describe and obtain information about the efforts of supervisors in leadership capability for effective learning. This research is a school action. The procedure in this research include planning, action, observation and reflection. The study consisted of two cycles of the four meetings. Subjects consisted of 10 teachers at SDN 19 Valley Crossing. Data were collected by using observation sheet. Data were analyzed using persentase. Hasil research shows that improving the professionalism of teachers in learning through effective leadership companion activities (mentoring) in SDN 19 Valley West Pasaman Melintang. Activity mentored teacher mentoring and assessment is given every day can increase the professionalism of teachers it can be seen from the results of the first cycle to the second cycle increased value is the average teacher in siklu 1 is 65.04 with less category sedangankan in cycle 2 of 86, 04.dengan category very well.Keywords: Increasing Professionalism, Effective Learning