It’s very important for the decision division to imitate fire behaviorquantitatively.Fire spread has the features of time and space.That means it mustbe established under space background data base and must be fulfiled by the helpof GIS and RS.The occurrence and development of forest fire are infuienced by someinternal and external factors Internal factors include fuel type

fuel moister and to-pography.By using these factors we created the time map of fire spread in pixel. External factors are mainly attributed to the infulence of climate. We determinedwhether the pixel would burn or not according to the map of burning probability.We used both Rothermel model and experiential model for fire spread Meanwhiledirectional factors such as slope and wind were also taken into account.Finally wecompleted the fire spread in microcomputer based on GIS.