現代科技發展日新月異，電腦、通訊和網路的結合，使得讀者之資訊需求量不斷增加;因此，現代圖書館面臨空前壓力。資訊社會中，資訊之傳佈與利用為圖書館最重要的功能。而資訊社會的新需求導致圖書館重新考量具任務、目標、服務、組織結構、館員任用、以及管理技術的調適與變革。 本文探討二十世紀以來，圖書館組織之理論、系統理論與圖書館環境、人力資源理論在圖書館組織之應用、圖書館組織與其內外環境的錯綜複雜關係，以及邁向二十一世紀資訊時代之際圖書館組織在其內外環境影響下所作的調適與變革。 從本文探討本世紀以來的圖書館組織，可以看出一九九O年代的圖書館，已在組織理論及結構方面作相當的創新與變革，如平行組織與平面組織即為其例證。而在邁向二十一世紀的社會，電子圖書館和虛擬圖書贈即將美夢成其之時，圖書館是否仍然維持目前約有形組織結構，是否將虛擬化，俾便達到以資訊之傳佈利用而不以資訊之典藏擁有為目標的圖書館服務，是目前眾所矚目的議題。本文乃拋磚引玉之作，甚願先進學者專家對圖書館組織有更精深的研究，是所期盼。

　　　　　Modern technology such as computer, communication, and network　has made a significant impact on the library information services in the 1990's. The information needs of library users have been increased enormously. Therefore the dissemination and access of information become the most important functions in modern library. In order to survive in the information age, library starts to evaluate its mission, objectives, services, staffing, organization, and management techniques. Library organization is one of the topics to draw the attention of library professionals. This paper is to study the theories of the libary organization, system theory and library environment, human resources theory and its applications to library, as well as library organization and its internal and external environments ever since 1900. Also studied are the changes and innovations already made by the library under the influence of external and internal environment in the past decade. This paper concludes that modern library has made some changes and innovations for its organization both in theory and in practice since 1980, parallel organization and flat organization are just two examples. Once the predicted electronic library and virtual library are coming into existence in the future, the library organization will be changed greatly, and information access rather than information holding will be the main function of library services. This paper is just a preliminary study of library organization in this aspect. The author do hope there will have more detailed studies about library organization that the library will be prosperous in the next century.