Legitimate sensor nodes may be captured by an adversary to extract important security information regarding shared secrets, cryptographic keys and so on. The adversary can easily launch node clone attack, which is an attack that an adversary attempts to add one or more nodes to the network by cloning captured nodes. This kind of attack imposes a severe threat to wireless sensor networks (WSNs). A novel scheme to detect the node clone attack in WSN by channel identification characteristic is presented, in which the clone nodes are distinguished by the channel responses between nodes. The proposed scheme aims at achieving fast detection and minimising the data transmission cost by taking advantage of temporal and spatial uniqueness in physical layer channel responses. In contrast to previous solutions, the proposed approaches feature nearly-perfect resilience to node clone attack with low communication and computation costs, low memory requirements and high detection probability.