A differentiated resource reservation (DRR) mechanism for optical burst switching (OBS),in which the burst assembly algorithm is combined with the resource reservation scheme,is proposed. Introducing the idea of“burst flow”and“piggyback request”respectively,a linear prediction-based assembly algorithm is used in the edge node to create a burst or burst flow,and different resource reservation manner are presented for per burst and burst flow in the core node. Simulation results show that the packet loss performance of OBS can be significantly improved.