Wireless Sensor Networks refers to a multi-hop packet based network that contains a set of mobile sensor nodes. Every node is free to travel separately on any route and can modify its links to other nodes. Therefore, the network is self organizing and adaptive networks which repeatedly changes its topology. The relations among nodes are restricted to their communication range, and teamwork with intermediate nodes is necessary for nodes to forward the packets to other sensor nodes beyond their communication range. The network’s broadcasting character and transmission medium help the attacker to interrupt network. An attacker can transform the routing protocol and interrupt the network operations through mechanisms such as selective forwarding, packet drops, and data fabrication. One of the serious routingdisruption attacks is Wormhole Attack. The main emphasis of this paper is to study wormhole attack, its detection method and the different techniques to prevent the network from these attack.