Provided is a method for transmitting a burst in an optical burst switching system, in which when a burst is generated at an originating node, a burst control packet is transmitted to a destination node by way of a plurality of nodes and then a data burst is transmitted after a pre-allocated offset time. The method includes the steps of obtaining an arrival time of data bursts that survive competition to occupy an output channel among data bursts transmitted to the next node by way of the current node using offset time information in burst control packets for the survived data bursts, checking whether an empty void is present between the survived data bursts by using the obtained arrival time of the survived data bursts, and generating a new data burst originating from the current node, inserting the newly generated data burst into the checked empty void, and transmitting to the next node. This method can improve channel utilization and maximize performance of the optical burst switching system.