分類法與主題法是圖書館編目工作，進行主題分析的主要工具。二者各具特色，相輔為用，旨在揭示圖書內容，提供讀者查找文獻。本文在闡述二者之特性，並述及美國國會圖書館及「國際圖書館電腦中心」 (OCLC) 對於分類法與主題法之研訂機制、系統建置等作為，進而分析我國有關分類法與主題詞表研訂及系統建置的現況與相關問題。本文認為LC及OCLC的做法頗有參考價值，今後國內對於分類表與主題表的內容要力求完備實用，且要隨時更新，以保持內容的新穎。另一方面，更要建置便捷的檢索系統以利使用。

Methodologies for classification and subject categorization are two aspects of library cataloging and act as important tools for analyzing subjects. While each possesses its own special characteristics, they complement each other. By pointing out the contents of a library's collection, these systems provide library patrons with the documents that they're seeking. This article relates each one's special characteristics and the defining mechanism and system establishment used by the US Library of Congress (LC) and the Online Computer Library Center (OCLC). This article takes this a step further by analyzing our domestic status of and problems with the defining and system establishment for classification and subject headings. I have found that the LC and the OCLC's methods are worth examining. From now on, we should strive to achieve complete applicability and make improvements as needed to the contents of our class headings and subject headings. We also need to establish a simpler search process that is user-friendly.