The paper states the necessity for hospital libraries to expand their promotion channels, introduces the new development trend of the library circle and promotion channels such as websites, micro-blogs, WeChat and mobile libraries, and explains the roles of these channels for hospital libraries. Also, it discusses how to choose a channel according to actual situations of a hospital and introduces measures for expanding the promotion channels from five aspects: special personnel in charge of channel promotion, good advertising through platforms, organization and management of promoted contents, highlighting initiative services and personalized services, etc.