The effect of forest on snow was evaluated by snow model. The snow model consists of a snowfall and snowmelt models. The amount of snowfall interrupted by the canopy was evaluated using the snowfall model. The heat balance method was used in the snowmelt model. LAI (Leaf Area Index) was used as parameter showing the effect of forest. As results, snow depth calculated by the model was almost corresponding to observed data. Applying this model to evaluate forest effects, dense forest can remain snow longer under the high temperature condition. This says that high LAI forest is useful for prevention of snowmelt retention.