Abstract: Digitizing library collections is the trend for the development of university libraries.However，the concerning law has some restrictions on fair use in terms of the scope，region and methods，which prevent the development of digital libraries.Many universities choose to purchase the digital data instead of developing their own digital resources.This paper analyzes the above difficulties in digitizing libraries and introduces concerning regulations of American law.And the authors suggest that we learn from Digital Millennium Copyright Act of the U.S.and introduce less tight restrictions on the purpose，region and methods of libraries′ “fair use” of the digital products so that digital resources in university libraries can be shared in the real sense.

Key words: library, copyright law, digitalization, special library collections, CALIS