According to the American education system, there are three types of middle schools: four-year system, six-year system and three-thirds system. Middle schools in the United States are mainly comprehensive, providing general and vocational education, as well as independent general middle schools, vocational and technical schools, specialized middle schools and other middle schools. Regarding the purpose of secondary education in the United States, 19 18 The American Secondary Education Reorganization Committee put forward? Seven principles? ：

(1) Maintain physical and mental health.

(2) Master basic learning skills.

(3) Become an effective member of the family.

(4) Develop employment knowledge.

(5) Being able to perform civic duties.

(6) Be good at using leisure time.

(7) Have moral quality.

The implementation of American middle school education generally revolves around three tasks of middle schools-teaching, guidance and service. Middle school courses are divided into two categories: one is academic subjects, such as English, social studies, science, mathematics, foreign languages, humanities and so on; The other is non-academic subjects, such as health, physical education, home economics, music, fine arts and crafts. The form of teaching organization is mainly grading system, and other grouping methods are also adopted.