The medium access control (MAC) protocol is designed only for single channel in the IEEE 802.11 standard. That means the throughput of the network is limited by the bandwidth of the channel. While multiple channels can be exploited by Multi-channel MAC algorithm to get more concurrent transmissions, the spatial reuse can be achieved by power control. In this paper, we combine the Multi-channel MAC protocol and Power Control together to exploit multiple channels and frequency reuse. The main idea of our proposal is to use IEEE 802.11 Power Saving Scheme (PSM) with different transmission power level used in the ATIM window and the data window. All nodes transmit ATIM/ATIM-ACK/ATIM-RES with maximum power while contending the data channel in the ATIM window, and use minimum required transmission power in the data window on their negotiated channels. The simulation results show that the proposed MMAC-PC can improve the network performance: aggregate throughput, average delay and energy efficiency.