A method and system for transmitting and receiving media according to the importance of a media burst in a PTT over Cellular (PoC) system are provided. The method includes transmitting a Media Burst Control Protocol (MBCP) Request message containing importance indication information by a sending PoC client: a controlling PoC server receiving the MBCP Request message, and if the importance indication information is contained in the MBCP Request message, determining that an important message will be transmitted, creating an MBCP Taken message containing the importance indication information, and transmitting the MBCP Taken message to a receiving PoC client via a participating PoC server: and receiving, by the receiving PoC client, the MBCP Taken message, and if it is determined that the importance indication information is contained in the MBCP Taken message, informing that an important message will be transmitted.