Demagnetization will appear when stepping motor internal operating temperatures exceed about 130℃

and causes decreasing of the output torque and out-of-step. A wireless sensor networks was applied to design a new type of stepping motor operating status monitoring system. In order to realize an easy and reliable monitor

an improved algorithm-directed diffusion protocol was introduced into wireless sensor networks system. Atmega128 L and CC2420 were adopted to design the sensor node. The monitoring system will alarm when surface temperature of stepping motor exceed 90 ℃

so as to take steps and guarantee the safe of field equipments. The experiment results indicated the monitoring system is effective

and can meet the requirement of monitoring.