We developed a modified fire effect model for representing the psychological pressure caused by the flame and smoke. Then, we applied the developed model on FDS+Evac to analyze the evacuation characteristics. When the developed model is used, the evacuees are distributed further away from the fire because the evacuees change the movement direction to evacuate safely. Therefore, the modified fire effect model is more reliable than the Helbing's model because some evacuees are move through the fire source when the Helbing's model is used. However, the additional studies are required for improving the reality of the modified fire effect model.