Abstract: Features of wormhole attacks in wireless sensor networks were analyzed. According to the features that some routes may be shortened and the number of neighbors of some nodes may be increased, a detection algorithm was proposed to detect wormhole attacks in wireless sensor networks. Some source and destination (SD) node pairs were firstly deployed at the edge zone. Then the route discovery process was launched to find dubious route with abnormally fewer hops. After that, each node on the dubious paths was detected by checking the number of its neighbors. If such a node had more neighbors, it could be made sure that the node was infected and there was a wormhole attack in the network. The infected nodes would be isolated from the network to avoid more damages. Experimental results showed that the proposed algorithm has low false positive and high accuracy.