Employed but unpublished. It is impossible to add a lot of new content (more than 50%) to this article and then submit it to other journals. One vote counts as one more vote.

Taking China Library Book Classification and Periodical Classification Table as the representative, the periodicals are divided into five basic categories.

In the basic category, it is divided into several categories. For example, social science is divided into general social science, politics, military affairs, economy, culture, science, education, sports, language, writing, literature, art, history and geography.

Understanding the core journals is of great significance. As far as editors are concerned, they can learn from core journals. As far as readers are concerned, establishing the consciousness of core periodicals can clarify the value orientation and improve their reading level. For example, students majoring in language and literature should first read core journals such as China Language and Literature Review, instead of putting the cart before the horse.

As far as libraries are concerned, core periodicals are of course the first choice for subscription under the limited funds. As far as the scientific research management department is concerned, it can make statistical analysis of the papers published by units or individuals in core journals as an important indicator to measure their academic level. Therefore, people often aim at publishing articles in core journals.