Huang Chen Chiu (in 1996) thought principal's responsibility for the school service plan, the teachers and administrators hires to send with to inspect, the teacher teaching direction, the teacher in office takes advanced courses, student's counselling, the business management, the financial control and the public relation. Principal is the student study and the school service development essential character, the school achievements is to the school leader's quality. ”How principal is, how school is.” If principal can familiar supervise the theory, friendly with supervises the skill, applies flexibly supervises the behavior, to principal individual career development, the school administration potency, the teacher teaching quality as well as the student studies the result and so on, has greatest being of help.