Don't belong. The American Science Citation Index (SCI) was founded by the institute for scientific information in Philadelphia in 1957, and it is a citation database created and published by institute for scientific information (ISI)1961+0. SCI (Science Citation Index), EI (Engineering Index) and ISTP (Science and Technology Conference Record Index) are three world-famous retrieval systems for scientific documents, which are internationally recognized as the main retrieval tools for scientific statistics and scientific evaluation, among which SCI is the most important and its founder is eugene garfield (,16, 1925 ~). China Science Citation Index (CSCI). To understand CSCI, we must start with SCI. The full name of SCI is Science Citation Index, which is a world-famous periodical literature retrieval tool published by institute for scientific information (ISI). Its publishing forms include printed periodicals, CDs, online databases and online databases on the Internet. SCI contains about 3,500 core journals published all over the world in the fields of mathematics, science, chemistry, agriculture, forestry, medicine, life sciences, astronomy, geography, environment, materials and engineering technology. ISI selects periodical sources through its strict periodical selection criteria and evaluation procedures, with a slight increase or decrease every year, so that the literature collected by SCI can comprehensively cover the most important and influential research achievements in the world. ISI refers to the most influential research achievements, which means that a large number of documents reporting these achievements are cited by other documents. Therefore, as a retrieval tool, SCI has set up a unique "citation index", which is contrary to the conventional practice of other retrieval tools to retrieve documents by subject or classification. That is, through the reference of the current document to the previous document, the correlation between documents and the influence of the previous document on the current document are explained. The above characteristics of SCI make SCI not only a document retrieval tool, but also a basis for scientific research evaluation. The total number of papers collected by SCI in scientific research institutions reflects the scientific research level of the whole institution, especially the basic research; The number of papers collected and cited by SCI reflects his research ability and academic level.