An apparatus and method for allowing a plurality of playback devices to stream content of a master device simultaneously is provided. When the master device selects one of the playback devices as a reference device and multicasts a synchronization packet to the playback devices, the playback devices determine a synchronization time by comparing their own synchronization packet reception time with a synchronization packet reception time of the reference device. When the master device streams content, into which a time stamp is inserted based on the time of the reference device, the playback devices play the content based on the determined synchronization time. Therefore, even when the playback devices have different network latencies from the master device, the playback devices may accurately perform synchronized content playback.