隨著數位圖書館計畫的推展與實施，後設資料(Metadata)已成為不可或缺的基礎研究與工作項目之一。本文採取比較法，以後設資料的全球發展趨勢為依據，探索數位典藏國家型科技計畫後設資料的發展與應用現況。本文發現主要有四項：第一，應用情形朝多元化方向發展，範圍同時兼具深廣度，並以結構性後設資料標準為主。第二，應用方式則是採取多種標準與平行策略。第三，在描述層面方面，以物(即典藏品)、人與地理空間為主。第四，以學科與社群為導向的後設資料核心集有逐漸增加的現象。

Metadata has become one of the fundamentals for digital library projects worldwide in recent years. With reference to the global trends of metadata development, this paper adopts comparison as the research methodology to explore the current metadata application and progress attained by the National Digital Archives program (NDAP) in Taiwan. Through this comparative study, four findings are in focus. Firstly, metadata applications by NDAP involve a rich diversity, including various communities, themes, data types, and data functions. In addition, the selected metadata standards by NDAP projects are primarily structured ones. Secondly, based on the strategy of parallel employment, multiple metadata standards are customized and interwoven for the applications of NDAP projects. Thirdly, metadata descriptions in NDAP projects are mainly focused on thing, person, and geo-spatial objects. Lastly, several common core sets of metadata, either on the thematic or on the community basis, have been gradually developed for metadata interoperability.