At present, there are two authoritative versions in China to identify the core journals published in China (excluding Hong Kong, Macao and Taiwan). First, China Institute of Science and Technology Information (hereinafter referred to as CITIC) publishes the Citation Report of China Sci-tech Journals once a year; The other is the Outline of Chinese Core Journals jointly edited and published by Peking University Library and Peking University Library Journal Work Research Association.

In the fourth quarter of each year, China Institute of Science and Technology Information publishes the ranking of scientific research papers of the previous year for universities and research institutes all over the country. The ranking includes the number of papers collected by SCI, Ei and ISTP respectively and the number of papers published by China journals. The last item refers to the number of papers published by each unit in the journals compiled by Citation Report of China Sci-tech Journals. Citation Report of China Sci-tech Journals takes1more than 300 Chinese and foreign sci-tech journals as statistical sources. The content of the report is to count and analyze many indicators of these journals, the most important of which is to classify and rank the "impact factors".

Overview of China Core Journals is published irregularly, with the second edition published at 1996, the 2000 edition published in 2000 and the 2004 edition published in 2004. Chinese periodicals including social science, natural science and other disciplines. Among them, the identification of core journals is comprehensively evaluated through five indicators.

The selection principle of statistical source journals in Citation Report of China Sci-tech Journals and the determination of core journals in Chinese Core Journals are based on different methods, so their definitions of core journals are not completely consistent.

Characteristics, area codes and subject classification numbers of general periodicals.

First, the main features:

There is a unified domestic serial number. The domestic unified serial number format is CNXX-YYY/Z, which consists of China country code "CN", newspaper registration number "XX-YYY" and classification number "Z". Where "xx" is the code of the region where the periodical publishing unit is located, "yyyy" is the serial number assigned by the publishing management department (the sequence range of periodicals is "1000-4999"), and "Z" is used to indicate the subject classification of periodicals.

Second, the area code:

1 1. Beijing 12. Tianjin 13. Hebei 14. Shanxi 15. Inner Mongolia autonomous region 2 1. Liaoning 22. Jilin 23. Heilongjiang 3 1. Shanghai 30. East province 4 1. Henan province. Hubei province. Hunan province. Guangdong province. Guangxi Zhuang Autonomous Region. Hainan province. Alternate number 48. Alternate number 49. Alternate number 50. Chongqing 5 1. Sichuan province. Guizhou province 54. Xizang Autonomous Region 6 1. Shaanxi province.

Third, the subject classification number:

D- politics and law; Electronic military; F- economy; G- culture, science, education and sports; H- language and writing; I- literature; j-art； K- history and geography; Introduction to natural science; O- mathematical science and chemistry; P- astronomy, earth science; Q- biological science; R- medicine and health; Agricultural science; T- industrial technology; TB- general industrial technology; TD- mining engineering; Te- oil and gas industry; TF- metallurgical industry; Metallurgy and metal technology; TH-mechanical instrument industry; TJ- weapons industry; Tk- energy and power engineering; TL-atomic energy technology; TM- electrical technology; Radio electronics and telecommunications technology; TP- automation technology and computer technology; Chemical industry; Ts-light industry, handicraft industry; Tu- building science; Television-water conservancy project; u-transportation； V aviation and aerospace; X- environmental science and safety science; Z- comprehensive books