Terrain texture is the important basis to distinguish different landform. Terrain texture analysis based on DEM has become one of the important parts of digital terrain analysis. However, the scale effect of DEM data on the terrain texture extraction has been mostly ignored in recent researches. In this paper, 6 sample areas from different landform types of Shaanxi Province were selected to make scale-effect analysis on the terrain texture by Gray level co-occurrence matrix (GLCM) model. The result shows that the parameters of slope data and hill-shading data are insensitive with the change of data resolution. Angular Second Moment (ASM) and Contrast (CON) have the strongest ability to distinguish different types of landforms.ASM is suitable for recognizing the detail terrain texture and CON is suitable for recognizing wide-range terrain texture in contrast. Our results could deepen the understanding of DEM based terrain texture and the scale effect of some other texture models will be investigated in the further study.