A gateway system for implementing access to various media is provided in the invention, and the gateway system includes: a communication media access module, for establishing a communication link with the corresponding media access network; a Media Independent Handover Functions module, for seamless handover between accesses to various media; and a handover decision module, for selecting a target network for the seamless handover. The gateway system may also include an authentication module, for sharing the authentication information of the User Equipment. Two methods for implementing access to various media are further disclosed in the invention. By the provided gateway system and methods, the User Equipment can access various media via the gateway system, seamlessly hand over between accesses to various media and achieve the access to a service network using the shared authentication information.