Intelligent retrieval of SinoMed refers to a retrieval function realized by intelligent algorithm in Chinese Biomedical Literature Database (CBM) and Western Biomedical Literature Database (WEM) of SinoMed system. This function can automatically realize the synchronous retrieval of search words, subject words corresponding to search words and subordinate words contained in subject words. When a user enters a search word, the system will automatically search the subject words and subordinate words related to the word, thus expanding the search scope and providing more comprehensive search results.