Abstract: Representation of tree is a difficult problem in 3D GIS．Tree differs from common objects in its obvious fractal character，being difficult to modeling with common approaches．Now，fractal is in common use to produce vivid effect of tree．But the data amount is too large for its application in GIS；using tree image instead of tree is another approach in common use，but in the close shot，tree image would give bad effect，and the essential characters of tree are ignored．In this paper，we put forward a new method，which combines the tree fractal model with image model using LOD technology．By this approach，we can preliminarily realize the high-speed visualization and vivid effect．