Legal deposit is an important way to collect documents for the library. The Library Act of Taiwan subscribes the necessity of depositing electronic resources, but publishers have been hesitant to do so. In order to understand the issue of legal deposit of electronic resources, systems in the U.S., U.K., Australia, Canada and Taiwan are taken as examples to explain the actual situation. In-depth interviews are pursued for a systematic investigation into the opinion of scholars, experts and digital publishers. It is expected that this will provide impetus and paradigms for an electronic resources legal deposit 8ystem in Taiwan's National Central Library.