Classroom management is one of the most essential but also one of the most difficult teaching techniques. When facing students with increasingly diversified backgrounds, classroom teachers should utilize appropriate classroom management strategies to create an optimal learning environment for the teaching process. Comprehensive high schools offer flexible study programs for students based on their aptitude and ability. Because the comprehensive high school is a new type of school in Taiwan, teachers are facing new management and teaching challenges. Therefore, in addition to classroom management proficiency, teachers need to adopt various management strategies such as: applying of classroom routines, familiarization of students, stressing of individualized instruction, preparation for teaching activities, communication with students, creating an optimal learning environment, and reacting to irregular student behaviors. By doing so the goals of career guidance for students, and effective teaching by the teachers can be reached.