Abstract: Improving the quality of channel listening is an effective way to reduce energy consumption and improve communication efficiency. PB-MAC(predict-base MAC), a novel low duty cycle and low collision asynchronous MAC protocol was presented. PB-MAC lowers sensor duty cycle by enabling senders to predict receiver wakeup times. An efficient prediction-based reconnection and retransmission mechanism was introduced to achieve low collisions and high efficiency retransmission. Comparison of PB-MAC on OMNet++ with RI-MAC and X-MAC was evaluated. Evaluated on scenarios with 50 random disposed nodes, the average duty cycle, consumed energy and average collisions for PB-MAC is 68.60%, 24.75% and 68.05% less than those of RI-MAC and 64.39%, 64.05% and 70.54% less than those of X-MAC respectively. In grid network, PB-MAC also outperforms RI-MAC and X-MAC protocols.