圖書館的線上公用目錄檢索系統（ Online Public Access Catalog, OPAC ）是 一般讀者最常接觸到的圖書館自動化系統，也是讀者對圖書館電腦化成果的主要印象來源。 個人化 OPAC 系統的發展是希望能針對每個不同背景、興趣的讀者，主動題供不同圖書資訊 檢索與推薦服務。這類系統強調主動、長期、與個人化的資訊服務，與傳統系統所提供的被 動、短期、一般性資訊服務不同。由於個人化的 OPAC 系統對圖書資訊服務預期將有很大的 突破與影響，因此本文只是拋磚引玉，介紹目前國際上相關研究概況，探討其可能的影響以 及提出一些個人化服務的設計構想。

　　　　　Library OPACs have long been the gateways between users and information. They present to users the achievements of library automation, and are the most widely-available automated retrieval systems and the first that many users encounter. The current trends in OPAC design can be toward user-oriented information service, which would provide individual service to fulfill different needs of users with a variety of backgrounds and interests. Comparing with the rather inactive, short-term and general information service on conventional system, this type of system focuses on active, long-term, and personalized service. To provide such a sustomized OPAC, the author proposed a framework of designing a personalized OPAC. Some recent developments and effects of personalized information service are also discussed.