This research is motivated by several facts in the field, the lack of trust level of principals in teachers, lack of good relationships In the school environment, the principal's ability to mobilize human resources in schools is still limited. The lack of attention and concern of the principal to mobilize teachers to carry out activities at school. Specifically, this study aims to explore, analyze and obtain data on: Planning, organizing, implementing, and evaluating the managerial competence of junior high school principals in improving teacher performance. Supporting factors and obstacles faced by the Principals of Sechool to improve teacher performance. The efforts of the Head of Sechool in overcoming obstacles to improve teacher performance. Impact of managerial competence of junior high school principals on teacher performance. The research approach used by the author in this study is a qualitative descriptive approach (Qualitative Descriptive Approach). The method used is descriptive method. The research technique used participant observation, in-depth interviews and documentation of research results, namely: (1) Planning has been carried out in accordance with applicable guidelines. This program is made in a team that involves several elements consisting of the principal, deputy principal, teachers who are assigned to be the school development team and school committee representatives (2) Organizing, is carried out in a balanced manner by prioritizing performance, competence and rank order (3). ) Implementation of managerial competence by seeking effective learning with. improve the quality of teachers, provide trainings. To see the quality of teacher performance, the principal carries out supervision, the school gives rewards and punishments a tradition. in carrying out his leadership with a democratic approach. (4) Evaluation of school principals in improving teacher performance by monitoring the evaluation of each activity that has been carried out, making reports on program implementation and following up on evaluation results, (5) there are supporting and inhibiting factors for the principal, both coming from the individual himself and from outside individuals such as from organizations (schools) or from outside the organization (6) Efforts made by school principals in facing obstacles in improving teacher performance, by revitalizing MGMP and MKKS, increasing professionalism, fostering discipline for educational personnel, creating harmonious working relationships, utilizing technology and information, reward and punishment, improving the quality of facilities and infrastructure, budget optimization (7) The impact of the implementation of the principal managerial competence in the schools was very good teacher performance.