Abstract: In this paper,the effect of the interpolation methods which include Shephard,continuous curvature splines in tension and Kriging method,has been contrasted in the area where height observations are sparse.Then by using continuous curvature splines in tension,time series of the polar ice sheets DEM was established based on the ICESat refined altimetry data set.Finally,speed distribution of polar ice sheets elevation change was given and was contrasted with the corresponding value obtained via cross-over point algorithm.