Satellite differential synthetic aperture radar interferometry (DInSAR) has two limitations, i. e. , spatio-temporal decorrelation and atmospheric influence, for the application of regional deformation mapping. This paper proposed a new approach called time series DInSAR based on permanent scatters (PS) to overcome the limitations, and the relevant mathematical model and computing method are also developed. With the proposed algorithm, the experiments were performed to estimate the subsidence velocity field over Shanghai using 26 ERS-1/2 SAR images acquired from 1992 to 2002. The deformation signatures, atmospheric delay and other errors were separated effectively, and the subsidence velocity field over Shanghai was also derived.