USN technology will be applied to various fields such as logistics, transportation, government, health, welfare and environment and will be settled down by basic infrastructure of a future society. In this study, we analyzed sensor networks structure based on IEEE 802.15.4 and implemented the sensor monitoring system using Zigbee modules. For implementation of real-time sensor monitoring system, we designed Linux-based development environment and the sensor-specific component. The result of this paper may be utilized in such areas lighting system, intrusion detection, fire detection, detection and notification of abnormal conditions.