MIMO system (multiple antennas at the transmitter and receiver) is capable of very high theoretical capacities. As an important space-time code, V-BLAST (vertical-Bell lab layered space-time) code has been researched recently. The important operation of V-BLAST system is cancellation. However the conventional detection algorithm requires time to execute linear combination nulling and successive symbol cancellation. The time delay enhanced if the number of transmit antennas increase. In order to avoid this obstacle, parallel symbol cancellation (PSC) was proposed. But the performance is degraded. In this paper, we propose a combination of SSC and PSC to improve the system performance