This study aims to discover: 1) The effect of transformational leadership towards the employees’ Organizational Citizenship Behavior (OCB), 2) the effect of organization culture towards the employees’ Organizational Citizenship Behavior (OCB), 3) the effect of affective commitment towards the employees’ Organizational Citizenship Behavior (OCB). The research objects were the employees of two BMTs in Surakarta Residence. This study is a quantitative associative research. The data were obtained using questionnaires which were distributed to 150 employees, but the questionnaires which could be processed were 123 respondents. The data analysis was conducted using SPSS 15 application. The result of the study showed that: 1) Transformational leadership did not affect in significantly positive towards the employees’ Organizational Citizenship Behavior (OCB), which was shown with he significance value of 0.375. 2) The organization culture did not affect significantly positive towards the employees’ Organizational Citizenship Behavior (OCB), which was shown with the significance value of 0.177. 3) The affective commitment had significant positive effect towards the employees’ Organizational Citizenship Behavior (OCB), which was shown with significance value of 0.000.