著作權法為晚近發展而出之相當實用之法學領域。為保障著作人權益及促進國家 文化之發展，乃有制定著作權法之必要。圖書館負有傳承國家文化發展之使命，其「重製」 行為有其必要性；因此，乃有以「公平使用原則」為依歸，使其「重製」行為，不致違法。 本文乃以該原則為中心，探討著作權法與圖書館之互動關係。

　　　　　Copyright Law is a recently developed practical legal field. To protect copyright owner's interests and promote national culture development, it is necessary to enact copyright law. Library has a mission to extend national culture, is "reproduction" behavior is inevitable; therefore, it is mandatory to use "Fair Use Doctrine" to legitimate its "reproduction" behavior. This article is to use the said doctrine to study the mutual relationship between copyright law and library.