This research was conducted aiming to find out and analyze Transformational Leadership and Leader Member-Exchange toward Organizational Citizenship Behavior with Affective Commitment as a Mediating Variable. The objects of the research were the employees of three BPRS in Yogyakarta among others are PT. BPRS Margirizki Bahagia, PT. BPRS Madina Mandiri Sejahtera, and PT. BangunDrajat Warga. This research was a quantitative associative research. In this research, the data was collected by distributing questionnaires to 80 employees in three BPRS in Yogyakarta. The method used for sample collection was saturation sampling. The data analysis technique used was SmartPLS 3.0. The results of the research show that: 1) Transformational Leadership has a significant influence toward affective commitment, 2) Leader Member-Exchange has a positive influence toward affective commitment, 3) Affective commitment has a positive influence toward Organizational Citizenship Behavior, 4) Transformational Leadership has a positive influence toward Organizational Citizenship Behavior, 5) Leader Member-Exchange does not have a significant influence toward Organizational Citizenship Behavior, and 6) Affective commitment completely mediates Leader Member-Exchange with Organizational Citizenship Behavior. However, it does not mediate Transformational Leadership with Organizational Citizenship Behavior.