Abstract: The traditional location privacy protection algorithms in wireless sensor networks can not get a well balance between the security and network energy consumption. To resolve this problem， a routing algorithm of random relay node was proposed on the basis of the fan-shaped region. The range of routing path was controlled by adjusting the size of the fan-shaped region. In order to protect the location privacy of the source node， a mechanism was adopted which could randomly select a fan-shaped sub-region as the optional area of the next hop. Simulation results showed that comparing with Phantom routing and other routing algorithms， the proposed algorithm can effectively protect the location privacy of the source node without affecting the data transmission ratio， and has lower energy consumption. At the same time， the algorithm has better flexibility， and the high security or low energy cost mode can be set according to the practical demand.

Key words: wireless sensor networks, location privacy, dynamic routing, random fan-shaped sub-region, low energy consumption