As traditional TOA Ranging needs a lot of hardware expenditures to achieve the node time synchronization, combining JN5121 wireless microcontroller and a new Distance Calculation Method which is based on Information lag, We construct a new wireless monitoring, positioning network which is based on Zigbee Protocol. As shown in the system-experiment, the new system does not need to achieve the node time synchronization, and has low power and stable performance, It meets the Low-density, low-accuracy, low-cost wireless network's demand.