In opinion, I believe that leadership had way to improve their personal, social, and professional lives. Facilitating student leadership competencies development directly and indirectly helps communities, societies, families and industries. The prior research showed that environment and involvement variables have positive significant effect on student leadership development. Also leadership attitude and leadership behavior have significant positive effects on student leadership development. But this study has showed that the two variables attitude and behavior leadership are mediator variables in student leadership competencies development. Therefore, the mediatory role of leadership attitude and leadership behavior shows the explanatory model. The individual indepth interviews and focus group used in this study have provided a structured time for participants to reflect on their experience, as demonstrated in several comments from student leaders. The indicators of triangulation and conceptual modeling showed the same results. Increasing (promoting) student leadership competencies development demands pays special attention to the following issues: systematic thinking (relationship orientation, ethics, learning orientation change centered, and cooperative leadership process), challenging the process, Inspiring a shared vision, enabling others to act, modeling the way and encouraging the heart. Colleges and universities need to recognize that leadership attitude and leadership behavior as important factors positively affect student leadership competencies development.