To efficiently implement the visualization of terrain data in GIS,a vi-sualization model of 3-D terrain based on the combination of fractal interpolationand Delaunay triangulation is proposed.By means of the model,not only the geo-metry accuracy can be satisfied and the characteristic of terrain are preserved,butalso the textures of terrain surfaces are nicely visualized.The spatial resolution ofthis model can be arbitrarily controlled by the scale,location and temporal parame-ters.The model is suitable for GIS visualization data handling and analyzing.