Abstract: The issue of coverage enhancement in Wireless Multimedia Sensor Networks (WMSNs) was studied. In WMSNs, nodes of video and image had limited view range and could monitor only part of the surrounding. Due to the large quantity of sensor nodes and the limitation of deploying methods, phenomenon of monitoring overlapping and blind area occurred frequently. Hence, to improve monitoring quality, optimizing the monitoring directions of the sensors was necessary. This problem was discussed in this paper, and based on the directional sensing model, a coverage enhancing algorithm called MCE was proposed. MCE used an improved particle swarm optimization algorithm and adjusted the directions of all sensors. Simulation results showed that, MCE algorithm improved the coverage greatly.