The purposes of the study ; 1. To study the needs of the principals and teachers in private Vocational Schools concerning educational supervision by Offices of the Private Education Commission to four subjects : Agriculture, Trade and Industry, business and Arts and Crafts. 2. To compare the opinions of the principals and teachers in private vocational Schools concerning the needs of educational supervision in 5 parts by Office of the Private Education Commission according to four subjects : Agriculture, Trade and Industry, business and Arts and Crafts. 3. To present the performance supervision in Private Vocational Schools at Certificate of Vocational Educational level to Office of the Private Education Commission. Research Procedures : The sampling used in this research consisted of three groups of persons : 150 principals, 300 vocational subject teachers and 150 general teachers in all vocational schools, totaling 600 persons from 260 vocational private schools. The instruments used in this study were a check list and a rating scale. The questionnaire was divided into 3 parts. Part one : the status of the sample. Part two : The items of five details of educational supervision. Part three : It was a rating scale and an open-ended concerning general problems and recommendations about the educational supervision. Six hundred copies of the questionnaires were distributed, and four hundred thirty-five completed copies or 72.50 percent were returned. The data were analyzed by using percentage, mean ( ), standard deviation (S.D.), and F-test. Finding and conclusings : 1. The opinions of the principals, vocational subject teachers and general teachers concerning the items about needs of supervision in 5 parts on Agriculture, Business and Arts and Crafts subjects. The opinions were at high level of needs of supervision. For items concerning about need of supervision on Trade and Industrial subject were at high level in all parts except the part of planning, evaluation and research in education. 2. Compare the opinions of three groups concerning the needs of supervision about Agriculture, Trade and Industrial and Art and Crafts subjects were not difference except about the Business subjects, the opinions was significant different at the .05 level.
3. For the effective supervision performance, the resource require to have the interaction of both participants in all parts of supervision. Expect the presenting information of the curriculum presenting the collection of instructional instruments, counseling about the academic problems and inform of the results of the vocational research to the principals and teachers. 4. Office of the private Education Commission should systematically perform the supervision which emphasized on academic matters by using all process of supervision.
