The objectives of this thesis were: 1) to study the current situation, desirable situation of supervision within secondary schools under the office of the Basic Education Commission and 2) to study the necessity of supervision within secondary schools under the office of the Basic Education Commission. The population were 2,358 secondary schools under the office of the Basic Education Commission. The sample size was determined by using Taro Yamane’s Table. The samples were 342 schools. The research instrument was Rating Scale. The reliability from total issue of Questionnaire was 0.976. The research was conducted as follows: study the current condition, desirable condition and the necessity of supervision within secondary schools under the Office of the Basic Education Commission. The research findings found that: The current situation, an overview of the scope of supervision within secondary schools under the Office of the Basic Education Commission was at “High” level. The component with the highest level of current situation was educational supervision. On the contrary, the component with the lowest level of current situation was development of media, innovation and digital technology. The overall desirable situation of supervision within secondary schools under the Office of the Basic Education Commission, was at “the Highest” level. The component with the highest level of desirable situation was educational supervision. On the contrary, the component with the lowest level of desirable situation was the development of educational institutions. In addition, the needs assessment of the scope of supervision within secondary schools, found that the highest level of need index was the component of media, innovation and digital technology development. On the contrary, the component with lowest level of need index was the aspect of curriculum development in educational institutions.