The study aimed to identify the role of the administrative supervisors in the activation of school development performance system in the basic education schools in the Sultanate of Oman from the point of view of school principals, and their assistants. This is could be achieved by answering the following questions: achieve the objective of the study, the researcher has designed a questionnaire consisting of (51) statements divided into five dimensions: planning, problem solving, dissemination of the organizational culture of the system, professional development and training, supervision, monitoring and evaluation. After examining the reliability and the validity of the questionnaire, it was distributed to a certain sample of (879) school principals and their assistants in basic Education Schools education schools in the Sultanate of Oman The study shows that: 1- The administrative supervisors practice their roles to activate school development performance system with moderate degree from the point of view of school principals and their assistants in Basic the Sultanate of Oman. 2-There are no statically significant differences at the level(a = 0.05)) in the responses of the participants about the role of the administrative supervisors in activation of school development performance system attributed to gender variable for the following dimensions (planning, ,dissemination of the organizational culture of the system, supervision, monitoring and evaluation. However, there are statically significant differences in problem solving and professional development and training dimension in Favor of males. 3-There are no statically significant differences at the level(α = 0.05)in the responses of the participants about the role of the administrative supervisors in activation of of school development performance system attributed to job variable for all dimensions. 4-There are statically significant differences at the level(a = 0.05))in the responses of the participants about the role of the administrative supervisors in activation of school development performance system attributed to experience variable for the following dimensions (planning, problem solving and professional development and training, supervision, monitoring and evaluation for the individuals that have short experience (less than 3 years) in the role of the administrative supervisors in activation of school development performance system. The most important recommendations of the study are: 1- Specify the tasks of the administrative supervisor regarding the school development performance system within the main tasks that set by the administrative supervising guide.. 2- Train the administrative supervisor using the training package of the system in order to transfer the impact of training to school principals, their assistants and the development and improvement team at school. 3- Reduce the supervision scope of schools of the administrative supervisor. 4- Lift the burden from the administrative supervisor and the committees that he participates in outside his main job. 5 -Include the planning and implementation process of the school development performance system in the tasks of the administrative supervisor and not only the following-up.