The research aimed to strengthen professional administrators in the 21st century for schools under the Office of the Basic Education Commission. The research was designed to gather data quantitatively and qualitatively with a total of 343 participants. For quantitative purpose, data were collected from the practical situations of 248 school administrators in 2016 academic year under the Office of the Basic Education Commission. For qualitative purpose, participants included 5 interviewers, 90 voluntary administrators, The research instruments were questionnaires have reliability =.973, the workshop pre-test and post-test have reliability =.946, interview forms have reliability =.972,and observation forms have reliability =.967 Statistical analysis included average, percentage, standard deviation, and content analysis. Research results were as follows: 1. Results on practical situations indicated the overall performance of the administrators was at high level. 2. Results from the workshop on developing strategies for the professional administrators in the 21st century revealed that the elements of the strategies were vision, mission, objectives, and goal. Strategies developed were concluded in six components, including 1) achievement motivation strategy included having clear concepts on strategy of achievement motivation, understanding on planning process, working towards goal setting, focusing on work outcomes actively, thinking creatively, comply economical philosophy, engaging innovations, revising for better results, and reporting the achievement, 2) good service strategy included understanding the core of good service, determining needs of services, setting service management system, encouraging mind services, and conducting service satisfaction, 3) self-development strategy included having knowledge on selfdevelopment, analyzing strengths and weaknesses, selecting appropriate ways for self-improvement, choosing variety resources, exchanging learning experiences with colleagues, and getting good choices for work improvement, 4) team working strategy included understanding of the concept of team work, comply by the rules of leadership and followers, taking part in planning collaboratively, accepting to others ideas, making decisions based on data, and having responsibility, 5) professional ethics and conducts strategy included recognizing professional ethics and conducts, respecting rules and regulation of social, being good model for the profession physically, verbally, and mindfully, and 6) integrating 3Rx8C skills strategy included R1: Reading in both Thai and English languages proficiency, R2: Writing at least two required languages fluently, R3: Arithmetic for think critically and reasonably, C1: Critical thinking and problem solving, C2: Creativity and innovation, C3: Cross-cultural understanding, C4: Collaboration teamwork and leadership, C5: Communication Information and media literacy, C6: Computing and ICT literacy, C7: Career and learning skill, and C8: Compassion. 3. Results on the evaluation the strategies for the appropriateness, possibility, and usefulness indicated at the highest level in all aspects and administrators indicated the satisfaction at high level.