Optical burst switching (OBS) is a new paradigm proposed to efficiently support the ever-growing broadband traffic over WDM networks. In OBS networks, an important issue is how to improve the efficiency of the scheduling algorithm. In this paper, a new control packet buffering scheme "pipeline system" is introduced to buffer a certain number of control packets in order to collect more information before scheduling is carried out. A new scheduling scheme "virtual scheduling technique" (VST) is subsequently proposed to be implemented together with the pipeline system to improve the overall performance in terms of the burst drop probability. The VST technique reduces unused voids significantly, while maintaining first-in-first-out (FIFO) processing discipline on the control packets.