An access network selection method in a communications network having access networks is disclosed that includes notifying devices in calling-side and called-side networks of the identifiers of currently available access networks and user preferences; making a list of candidates for an access network to be assigned to the called-side terminal, and transmitting the list to the device in the calling-side network; determining an access network to be assigned to the calling-side terminal in response to reception of the list, and notifying the calling-side terminal of the determined access network; notifying the device in the called-side network of the type of the access network assigned to the calling-side terminal; and determining the access network to be assigned to the called-side terminal in response to reception of the signal of the type of the access network assigned to the calling-side terminal, and notifying the called-side terminal of the determined access network.