The law on intellectual property in general and copyright, in particular, is a subject of increasing interest in today’s society, particularly in the information and internet explosion era. To prevent infringement and effectively protect copyright in the online environment, Vietnam’s copyright law contains numerous provisions, including regulations pertaining to service provider responsibilities. This article examines the international and domestic legal bases for the liability of social network service providers (a type of internet-based intermediary service) in the fight against harmful copyright violations by the users of the service. Thus, the authors will identify several deficiencies in the existing Vietnamese copyright law. The article also analyzes comparable provisions in the national copyright laws of China and Singapore to draw lessons for enhancing Vietnamese copyright law on the same issue.