本研究旨在探討國家圖書館數位保存計畫之促成因素與相關問題，藉由比較研究之描述、解釋、併排與比較四步驟，研究美國與澳洲國家圖書館數位保存計畫之內涵，瞭解美國國會圖書館與澳洲國家圖書館在數位保存活動中扮演的角色、任務、法定寄存制度、數位保存計畫背景與促成因素等，歸納數位保存策略與典範，以提出我國發展數位保存計畫之建議與參考。 研究結果歸納促成美國與澳洲國家圖書館數位保存計畫發展的15項共同因素與3項不同因素。共同因素為：1.兩國皆因著作權法促成國家圖書館擔負法定寄存的責任；2.重視數位保存問題；3.重視數位資源法定寄存；4.數位資源採自願寄存協議；5.落實國家數位保存計畫；6.落實網站典藏保存計畫；7.採合作蒐集數位資源的策略；8.研訂所需描述性後設資料標準；9.採用多種Metadata架構；10.研訂保存性後設資料標準；11.數位保存技術策略；12.採用唯一的數位保存官方標準OAIS參考模式；13.採用HTTrack網站擷取工具；14.重視數位資源的永久取用；15.合宜的數位資源取用策略。不同因素為：1.國家數位保存計畫發展方式不同；2.網路資源典藏計畫不同；3.數位資源選擇決策不同。 本論文結論歸納發展國家數位保存應考量下列議題：1.國家圖書館數位保存的重要性；2.法定寄存制度與數位資源寄存問題；3.數位保存計畫推動；4.數位資源館藏政策與選擇指南；5.網路資源編目標準；6.Metadata標準；7.描述性後設資料；8.保存性後設資料；9.數位典藏庫；10.數位保存策略；11.數位保存取用與服務；12.數位保存成功因素與策略。 最後建議：1.加強原生數位資料研究；2.國家圖書館推動我國數位保存計畫；3. 建置我國網站典藏先導計畫；4.訂定數位館藏發展政策；5.訂定數位保存政策。 / The purpose of the study is to analyze the factors that helped to materialize the national library digital preservation projects. Through description, interpretation, juxtaposition, and comparison, this study research the concepts of the digital preservation projects from Library of Congress and National Library of Australia, which include the role, the mission, the legal deposit policy, the background, and the relevant factors of the digital preservation standards and strategy. Finally come up with the suggestion of the digital preservation projects of our own. The results of this study include 15 common factors and 3 different factors. The common factors are: 1.The national libraries are responsible for the legal deposit policy due to the copyright act；2.Emphasize on the digital preservation；3. Emphasize on the legal deposit policy；4.There is no common agreement on digital resources deposit policy；5.Carry out national digital preservation projects；6.Execute the web capture projects；7.Adopt the strategy of collecting digital resources together； 8.Construct the descriptive metadata standards；9.Adopt several metadata schemas； 10.Construct preservation metadata standards；11.Digital preservation strategy；12. Adopt official digital preservation standard OAIS；13.Adopt HTTrack web capture tool；14.Emphasize on the permanent access of the digital resources；15.Appropriate digital resources access strategy. The different factors are: 1.The development of the national digital preservation projects；2.The collection of the web-based resources projects；3.The selection decision of the digital resources. The conclusions of the study are: 1.The importance on digital preservation of a national library；2.The issues of legal deposit policy and the deposition of the digital resources；3.Successfully promote the development of a digital preservation project；4.Digital resources collection policy and selection guidelines；5.Web resources cataloging standards；6.Metadata standards；7.Descriptive metadata；8.Preservation metadata；9.Digital repository；10.Digital preservation strategy；11.Access and services of digital preservation；12.Succesful factors of promoting digital preservation projects. The study makes final suggestions as follows: 1.Emphasis on the research of born digital materials. 2. Promote national central library to develop our national digital preservation projects. 3. Construct the web-archiving pilot project. 4. Establish the digital collection development policy. 5. Establish the digital preservation policy.