In IEEE 802.11 standard, the use of multi-channel is one of the most important characteristic features contributing to the improvement of the overall network throughput. However, the channel utilization based on the use of multi-channel is relatively low because most medium access control (MAC) protocols were designed based primarily on the application of non-overlapping channels. This paper analyzes the channel utilization for the schemes using both non-overlapping and overlapping channels. Based on the analysis, we propose a scheme to exploit overlapping channels with collision avoidance mechanism. The proposed scheme makes use of the non-overlapping channels to increase the network throughput and it also takes into account the transmissions on different channels in order to maximize the throughput. Simulation results verify the effectiveness of the proposed scheme.