The present invention provides an IMS-based streaming media network system comprising: a streaming media service enabler configured to provide streaming media service description information to a user terminal; an application server configured to send a media resource request after the user terminal selects a streaming media service based on the service description information provided by the streaming media service enabler and after receiving a streaming media service request sent from the user terminal, and to provide the user terminal with information on a media resource delivery processing function entity storing streaming media contents after acquiring the information on the media resource delivery processing function entity; and, a media server configured to provide the application server with the information on the media resource delivery processing function entity storing the streaming media contents, based on the media resource request sent from the application server. The present invention further provides an IMS-based streaming media service enabler and streaming media service realization method. The present invention addresses the problem of realizing streaming media services on the basis of IMS-based network architecture.