School discipline is in crisis. This paper attempts to figure out the importance of school discipline in school effects research and effective school research. In some major studies on school effects, e.g., Brookover et al (1979), Rutter et al (1979), variables and factors related to school discipline are found to be associated with student achievements. Brookover et al(1979) found out that the social-psychological academic climates which are composed of expectations and evaluations held by school principals, teachers and students toward each other group was measurably associated with academic achievement. This school climate is a foundation of school discipline. Rutter et al (1979) were more specifically concerned with the relationship between school discipline and school outcomes including academic achievement. They found that the relationship was significant. Many effective school studies found out that order and discipline are one of the important charateristics of effective schools. They also suggested detailed tips for effective discipline. Based on the findings from school effects studies and effective school studies, the principles and directions of school discipline can be summarized as follows: 1) The orientation of students toward autonomous self-control of behavior is more desirable as school discipline than oppresive discipline by school adults. 2) A formation of comprehensive atmosphere formed with discipline-conducive elements is more desirable than individual skills or techniques of discipline. 3) A better discipline is the one in which all school members participate. 4) The process of discipline has to be paid attention to rather than to outcomes. 5) The rules of discipline should be clearly presented to school members and their applications should be fair, equal, and consistent to every student. 6) The positive reward and appraisal is a more effective method of discipline than punishment.