Abstract: To track the target with acoustic characteristics in wireless sensor networks, the acoustic source localization algorithm based on time delay estimation is proposed, In this algorithm, the generalized cross correlation (GCC) is employed as the time delay estimation algorithm, and a revised spherical interpolation (RSI) algorithm is presented for acoustic source localization with a less computational complexity. Then a target tracking prototype system using IRIS sensor nodes is implemented. Experiment results demonstrate that the prototype system can effectively track the target and improve the target tracking precision.