The purposes of the research were: (1) to study the factors of Educational Management System in Small Primary School; (2) to investigate current situations problems and guidelines of developing educational management in small primary school; (3) to develop Educational Management System in Small Primary School; and (4) to examine the results of usage Educational Management System in Small Primary School. The research was comprised of four phases: Phase 1 studying the factors of educational system in small primary school; Phase 2 Investigating current situations problems and guidelines of developing Educational Management System in Small Primary School; Phase 3 Developing educational system in small primary school; and Phase 4 Examining the results of usage educational system in small primary school. The instruments used for data collection in this study were a note-taking form, a questionnaire, an interview and an observation form. The statistics used for data analysis were mean, percentage, standard deviation and content analysis. The results of the research found that: (1) The factors of educational system in small primary school comprised of 4 main aspects: (a) Input including with eight sub-factors; (b) Process including with two sub-factors; (c) Output including with two sub-factors; and (d) Feedback including with one sub-factor; (2) The results of studying current situations and problems revealed that: There are 10,877 small primaries. The problems revealed that administrators lacked of supervision and did not followed up development of student's quality, teachers did not clear about student-centered learning, parents and community lacked of cooperation in development of student's quality and students' quality were lower than benchmark. The guidelines to develop found that both administrators and teachers needed to develop teachers in student-centered learning, curriculum in learning of teachers, media and technology, learning sources for learner's learning and to ask for parents' cooperation in development of student's quality; (3) Educational Management System consisted of 4 main aspects, 13 sub-factors including with 42 indicators; (4) Evaluating system factors by experts, the results revealed that there were the highest in every factor in 80%. The findings of evaluation system and manual of Educational Management System found that it was higher than 80%; and (5) The examining of usage Educational Management System revealed that pre-treatment of usage educational management system was in the "least" level. However, post-treatment of usage educational management system was in the "most" level.