Abstract: As agriculture predators cause substantial damage to agricultural crops, an intelligent bio-acoustic frightening system has been designed against agriculture predators. In this system, the Wireless Sensor Networks (WSN) was used as communication and detection platform, and embedded system based on ARM9 MPU and AT89C51SND1 were used as hardware platform of the central-controller and the actuators. Agriculture predators were detected by the pyroelectric infrared sensor with its type determined according to the Crop types-Environment-Predator-Natural enemy model, then the actuator broadcasted the call of relative natural enemy to accomplish intelligent repelling against different agricultural predators. Compared with present repelling method which can be easily habituated by target predators, this system is more effective and covers lager area, and with better expansibility and flexibility. It is an intelligent and pollution-free solution against agriculture predators.