Abstract: A new algorithm for jointly estimating the clock bias and the position of a source node is developed to address the asynchronous problem of time-of-arrival (TOA) based localization. The proposed methods consist of two processing stages. First, the initial estimates of the clock bias and node location are obtained based on the weighted least square (WLS) criterion by introducing an intermediate variable. Then, a linearcorrection technique is used to revise the initial estimation. Theoretical analysis and experiments results indicate that compared with the traditional methods, the proposed algorithm has a closed-form solution and can achieve the Cramer-Rao lower bound (CRLB) for both cases where the source node lies within and outside the sensor -array with a higher localization accuracy.