China Library Classification is a set of classification system widely adopted by libraries and information circles in China. It aims to scientifically classify all kinds of books, materials and documents according to their subject contents, so as to facilitate readers to find and use them.

This classification was first determined in 1956, and has been revised and improved many times. At present, China Library Classification has developed into a three-level classification system including 24 major categories, 244 middle categories and 3205 sub-categories. It is characterized by combining the advantages of western book classification, and also conforms to China's national conditions and cultural traditions, and has wide applicability.

The classification principles of China Library Classification mainly include the following points:

First, the principle of classification of theme ideas. According to the content of the works, the macro classification fully embodies the relationship between knowledge and social productive forces.

Second, the principle of series classification. Classify books and periodicals continuously and systematically to form a scientific and reasonable whole.

Third, the principle of aggregation classification. Gather books and periodicals under the same theme, and establish and pay attention to the internal hierarchy of each theme.

Fourth, the principle of classification. The establishment of multi-level classification can meet readers with different levels and needs and their research needs.

Five, the general classification principle. The classification number should accurately indicate the category, theme and characteristics of books and periodicals.

The advantages of China Library Classification are clear, simple, easy to understand and operate, and it is widely used in China, which fully reflects the China people's thirst for knowledge and cultural resources and their understanding of scientific classification. It not only provides readers with convenient and fast retrieval means, but also promotes the utilization and dissemination of information resources, making positive contributions to the development of China's knowledge industry.