Abstract: For permanent scatterer and small baseline subsets need no less than 20 SAR images to obtain reliable results,time series interferogram stacking method is used to detect the ground subsidence of Yancheng City.In order to minimize the effects of atmospheric delay error,structure function is used to extract the interferograms which have small atmospheric effects.The ground subsidence of Yancheng City during the period of 2003-12~2009-05 is obtained by 13 ASAR images.The results show that there are 4 subsidence funnels in Yancheng downtown during the period of 2003-12~2005-11.New subsidence funnels appear and local subsidence rate increases during the period of 2008-12~2009-05.