For the analysis of native environment of plants in a forest,we need PAR data at various land cover. A shielding situation of direct PAR has especially affected a growth of plants in a forest floor.The method using hemispherical photograph is normally used to estimate the solar radiation in a forest floor.This method calculates sky view factor from hemispherical photograph and then estimates solar radiation. However, this method has the limitation that solar radiation can only be estimated at shooting point of the hemispherical photograph. Voxel model of a forest has a potential to solve the limitation of this method because it can have a shielding factor as an attribute value and can create a virtual hemispherical photograph at any points in the forest floor.The aim of this study is to simulate the PAR in a forest floor using the virtual hemispherical photograph, which is created from voxel model of the forest.As the result,there was a correlation between the distribution of annual integrated solar radiation under the tree and the distribution of plant cover.This proposed method can expect to utilize the analysis of native environment of plants.