The invention discloses a method for building time-shifting television service and an entity with the time-shifting television medium function used for realizing the time-shifting television service in an IMS network. The method of the invention comprises the following steps: receiving medium negotiation contained content delivery channel information and content control channel information initiated by a terminal by the entity with the time-shifting television medium function, building the transmission connection between the terminal according to the medium negotiation results, receiving the medium playing requirements transmitted by the terminal through the transmission connection, and transmitting medium information corresponding to the medium playing requirements to the terminal according to the content delivery channel built by the content delivery channel information. The invention further provides the entity with the time-shifting television medium function. The method can realize the time-shifting television service in the IMS network.