統一醫學語言系統為美國國家醫學圖書館自一九八六年開始研發之計劃，其目的在提昇系統之能力，使系統能了解讀者在生物醫學方面的問題意涵，並進而幫助讀者檢索及整合相關資訊。 　　統一醫學語言系統共設計了四個知識庫，分別為泛索引典、語意網路、資訊來源圖及專家語典。此外為了方便擷取該系統之資料另發展一知識源伺服器。本文針對上述四種知識庫及伺服器，分別介紹其功能、建置理念與內涵，並對其未來發展與在國內應用的可能性加以探討。

　　　　　Since 1986 the National Library of Medicine has begun a long term research project to build the Unified Medical Language System. The purpose of the UMLS is to improve the capability of the system to realize user's biomedical queries and further help retrieve and integrate relevant information. To achieve the goals of the UMLS project, NLM designed four knowledge soures : Metathesaurus, Semantic Network, Information Source Map, and Specialist Lexicon. In this paper, we introduce the development assumption and strategy of the UMLS and the implementation of the four knowledge sources. We also try to analyze the possibilities of applying the four knowledge sources of the UMLS to the present information environment in Taiwan. We hope that this paper is just a beginning for us, socalled information managers, to think about how to build a powerful Chinese database.