In the recent information age, copyright protection has been attracted more and more attention. With the increasing number of international transactions, disputes arising from foreign-related copyright are more frequent. Due to the fact that principle of territoriality plays a pivotal role in the area of copyright protection and there is not a universal copyright law in the world, a work protected in one state may be unprotected in another state, or the level of protection is different from country to country. As a consequence, it is crucial to determine which law governs a transnational copyright case. Traditionally, it is recognized the lex loci protectionis, meaning the law of the place in which the protection is sought, mirrors the territoriality of copyright. And thus it is generally regarded as the most reasonable choice-of-law rule for copyright disputes. However, the lex loci protectionis is challenged in the digital world. Apart from the lex loci protectionis, there are various choice-of-law rules adopted by different national states to copyright cases. Besides, the approach of dépeçage is often adopted to determine the applicable law. In this approach, separate choice-of-law rules are applicable to different parts of copyright (e.g. validity, existence, ownership, infringement, contract, etc.). The lex originis is often regarded as the most competitive alternative method, especially in the field of initial ownership of copyright. Yet the lex originis has its own disadvantages as well. As a matter of fact, none of these approaches are perfect. The problem of choice-of-law rules in the field of copyright has become a hot topic nowadays. Several relevant provisions are stipulated by codes and academic legal instruments, especially in the EU and the US. It is significant not only to establish a series of choice-of-law rules which are most suitable for copyright cases, but also to harmonize choice-of-law rules of different states and thus the applicable law to a particular copyright case is definite no matter where the case is heard. In China, the academic study of this topic started lately. Nevertheless, the choice-of-law rules on intellectual property have been legislated currently, but they still have room for the improvement.