The objective of this qualitative research were : to study the phenomena and guidelines for school administration towards excellence in extra-large secondary schools: a case study of Khon Kaen Wittayayon School. The key informants were 1 director of the school, 11 administrative personnel, 8 heads of learning groups, and 1 head of student development activity department, a totally of 21 persons. The instruments used were a semi - structured interview form, document study, field trials with in-depth interviews, participatory and non-participant observation, tape recording, field notes and photography. Data analysis by content analysis, data validity checking using triangular method (triangulation). The research found that: 1. The phenomenon of school administration towards excellence of Khon Kaen Wittayayon School Summarized as follows: 1.1 The vision of the school organization, Mission and goals Policies have been formulated and promoted to continually improve the quality of education to achieve excellence and sustainability. 1.2 Strategic Planning School of Strategic Planning for Educational Management Development with the principles of PDCA by using the involvement process of personnel inside and outside the school By SWOT Analysis to continue operating. 1.3 Focusing on learners, the school conducted a survey, listening to opinions and assessing the needs of learners and stakeholders to improve school quality and develop curriculum and learning management. 1.4 Measurement, Analysis and Knowledge Management, the school has appointed a working group to analyze the school's performance, review to assess challenges ability and lead to further development of change. 1.5 Focusing on personnel, the school promotes and develops the capacity of teachers and personnel to have knowledge, competency, psychology, morality, ethics and desirable characteristics to be good role models for students. 1.6 Operational Focus, the school uses the KKW Model quality management system and determines the system to continuously improve the performance according to the PDCA cycle. 1.7 Outcomes, the school has developed everything into excellence and uses a management system that is aimed towards sustainable success. 2. Guidelines for school administration towards excellence of Khon Kaen Wittayayon School 2.1 The leading: the administrations must understand the context of the school that has challenges in general, to be the information on the decision making to determine the direction of the school development towards excellence. 2.2 Strategic planning : the school should have been analyzed of the school environment to be current and consistent. 2.3 Focusing on students; the School should develop curriculum and educational management that focuses on learners to be excellent in all areas. 2.4 Measurement, analysis and knowledge management; the school should have an exan nmmination. improve teaching and learning management to be efficientcy and quality, systematically and sustainably. 2.5 Focusing on Personnel, schools should be encouraged, continuously support the quality development of personnel. 2.6 Operational focus; schools should plan information using and integrate them to achieve school results. 2.7 School outcomes; should include progress indicators In order to improve the educational process and services to be effective and sustainable quality.