機讀編目格式(Machine-Readable Cataloging，簡稱MARC)是圖書館長久以來用於組織書目資訊的必備工具。內圖書館普遍採用中國機讀編目格式(CMARC)來處理中文資料，然而我們對於CMARC欄位的實際使用情形卻沒有足夠的了解。本文以Mone與Benaradino所進行的MARC研究為基礎，由臺大圖書館之圖書類型書目資料檔取樣，進行CMARC欄位用情形之分析研究。研究結果發現，本樣本的1,256筆CMARC書目資料中，有64%的分欄未被使用，而且有超過80%的使用集中在7%的分欄。根據研究結果，作者提出一些供CMARC修訂單位、各圖書館編目單位以及編目館員參考的建議。

The Machine-Readable Cataloging (MARC) format is an essential tool for libraries to store and manipulate bibliographic information. In Taiwan, many libraries use CMARC as a major means to process bibliographic data. Still, we do not have enough understanding about the actual utilization of content designation in CMARC. Based on the research of Moen and Benardino, this study intends to examine the utilization of the fields and subfields of CMARC. A sample of 1,256 records was extracted from the bibliographic database of the National Taiwan University Library. The results show that 64% of all subfields designed for book materials were never used, and 7% of subfields account for more than 80% of the utilization of content designation.