A method of providing a packet network-based Multimedia RingBack Tone, MRBT, service, the method being performed to provide an MRBT, designated by a called party, to an originating Mobile Station, MS, over a packet network, comprising: a first step of, if an originating Mobile Switching Center, MSC, requests information about a location of call termination from a Home Location Register, HLR, when the originating MS originates a call, the HLR checking (S403, S503) MRBT service status of a relevant called party, and transmitting (S404, S504) an MRBT service request message, including a calling number and a called number, to an MRBT server for managing information about content designated by MRBT service subscribers when the called party is a subscriber to the MRBT service and the MRBT service is activated; a second step of the MRBT server checking (S405, S505) MRBT content Uniform Resource Locator,URL, information of the MRBT designated by the called party, and returning (S406, S506) an MRBT service response message, including the MRBT content URL information of the called party, to the HLR; a third step of the HLR obtaining (S406, S506) call termination routing information from a terminating MSC, and transmitting (S409, S509) a call termination location information response message to the originating MSC, with both MRBT service ID information and the MRBT content URL information of the called party included in the call termination location information response message, the MRBT service ID information indicating that the called party is a subscriber to the MRBT service; a fourth step of the originating MSC transmitting (S411, S511) the MRBT content URL information of the called party to the originating MS on a basis of the MRBT service ID information included in the call termination location information response message; and a fifth step of the originating MS determining (S412, S512) whether MRBT content, corresponding to the MRBT content URL information of the called party, is stored in memory thereof, and accessing the MRBT content URL information of the called party, downloading the MRBT content of the called party, and playing and storing the downloaded MRBT content if it is determined that the MRBT content is not stored in the memory, and playing the stored MRBT content of the called party if it is determined that the MRBT content is stored in the memory. a first step of, if an originating Mobile Switching Center, MSC, requests information about a location of call termination from a Home Location Register, HLR, when the originating MS originates a call, the HLR checking (S403, S503) MRBT service status of a relevant called party, and transmitting (S404, S504) an MRBT service request message, including a calling number and a called number, to an MRBT server for managing information about content designated by MRBT service subscribers when the called party is a subscriber to the MRBT service and the MRBT service is activated; a second step of the MRBT server checking (S405, S505) MRBT content Uniform Resource Locator,URL, information of the MRBT designated by the called party, and returning (S406, S506) an MRBT service response message, including the MRBT content URL information of the called party, to the HLR; a third step of the HLR obtaining (S406, S506) call termination routing information from a terminating MSC, and transmitting (S409, S509) a call termination location information response message to the originating MSC, with both MRBT service ID information and the MRBT content URL information of the called party included in the call termination location information response message, the MRBT service ID information indicating that the called party is a subscriber to the MRBT service; a fourth step of the originating MSC transmitting (S411, S511) the MRBT content URL information of the called party to the originating MS on a basis of the MRBT service ID information included in the call termination location information response message; and a fifth step of the originating MS determining (S412, S512) whether MRBT content, corresponding to the MRBT content URL information of the called party, is stored in memory thereof, and accessing the MRBT content URL information of the called party, downloading the MRBT content of the called party, and playing and storing the downloaded MRBT content if it is determined that the MRBT content is not stored in the memory, and playing the stored MRBT content of the called party if it is determined that the MRBT content is stored in the memory.