Teachers' professional quality includes teachers' professional knowledge besides teachers' professional ethics, which is divided into four parts: ontology knowledge, conditional knowledge, extensive cultural knowledge and practical knowledge.

1. Teachers' ontological knowledge, also known as "subject expertise", refers to teachers' knowledge of teaching subjects. For example, the knowledge of language and literature possessed by Chinese teachers. Mathematics knowledge possessed by mathematics teachers, etc.

2. Teachers' conditional knowledge, also known as necessary knowledge of educational science, mainly refers to the knowledge of pedagogy, psychology and educational management that teachers must possess. This knowledge provides the foundation of pedagogy and psychology for teachers' teaching design and implementation.

3. Teachers' extensive cultural knowledge is the basis of teachers' professional knowledge structure, including humanistic knowledge, social science and natural science knowledge, and basic artistic accomplishment.

4. Teachers' practical knowledge refers to teachers' knowledge of classroom situations and teaching methods of related disciplines in the process of realizing purposeful teaching behavior. It includes an understanding of the relationship between specific teaching objectives, teaching situations, teaching strategies and methods, which helps teachers solve the problem of "how to teach specifically".