Abstract: DEM(digital elevation model) and terrain analysis based on DEM are scale-dependant.DEM scale transition that deducting other more scales from a fixed resolution is always met in application such as hydrology,soil science,and geomorphology.We present a new DEM scale transition with point spread function which is of image blur.The presented method is carried out by the spatial convolution between DEM with fixed resolution and simulated point spread functions with different radiuses.Then elevation statistics,contour-matching,and autocorrelation are designed to evaluate the transformed DEM.Finally the results achived with the proposed method were compared with the results of nearest neighbor assignment,bilinear interpolation and cubic convolution in the two different study areas.The result shows that the proposed method is effective.