The present invention relates to a system for transmitting and receiving audio, particularly, to a method and apparatus for transmitting and receiving of object-based audio contents, which packetizes audio objects having the same characteristic. To achieve the above, the present invention includes filtering a plurality of ESs according to common information, adding a packet header to the respective filtered ESs and generate ES packets, aggregating all the generated ES packets and then adding a multi-object packet header to the aggregated ES packets to generate an object packet, and multiplexing the generated object packet, packetizing the multiplexed object packet according to a transmitting media and transmitting the packetized object packet.