ZigBee technology, based on the IEEE802.15.4 protocol, is a newly developed short range wireless communication technology with the merits of low cost, low power consumption at comparably lower data rate. Mobile objects tracking system based on wireless sensor network becomes a hot topic recently. The paper, aiming at wireless sensor network, investigates the tracking system. Based on RSSI and location engine, the tacking system is implemented. The system includes three parts: hardware platform preparation, communication program of nodes and PC monitor software. The core of hardware platform is CC2430 and CC2431. The exploitation of node communication program is based on Z-Stack protocol stack which is provided by TI. The paper goes into details of the nodes communication flow. Elaborate solution is proposed in this paper. In the end, practical test is implemented. This part analyzes the influence of the different location area consisted by reference nodes to the accuracy and stability of blind nodes.