China's discipline catalogue is divided into three levels: discipline category, first-class discipline (professional category) and two disciplines (professional category). Philosophy, economics, law and other disciplines have first-class disciplines, such as mathematics, physics and chemistry. The first-level discipline consists of two disciplines, for example, mathematics consists of basic mathematics, mathematics and applied mathematics.

Discipline and specialty are two concepts, discipline refers to the knowledge system, specialty refers to the employment system, and specialty extends from a discipline. In order to have a relatively independent professional knowledge system, the two disciplines have formed a number of clear research directions.

The first-level discipline and two disciplines are the relationship between inclusion and inclusion. Generally, there are several two disciplines under a first-level discipline. For a simple example, if mathematics is a first-level discipline, there are two disciplines under the first-level discipline: basic mathematics science, information and computing science, mathematics and applied mathematics. A first-level discipline can be simply understood as a "department" or "enrollment category" of a university, and two disciplines can be simply understood as a major or direction.