For prompt response and consequent measure at the environmental radiation emergency of nuclear installations which include nuclear power plants, needed is rapid and movable monitoring system which can display and analyze distribution of overall environmental radiation around surrounding area. At occurrence of the nuclear emergency including the disastrous accident like the Fukushima Nuclear Power Plants accident or detected radiation in the public city environment, the comprehensive understanding of rapid radiation distribution, which has measurement error, is essential for the quick measuring on the public protection in the surrounding area. For that, 2D and 3D contour mapping method are developed for the distribution of natural radiation, major artificial radiation (137Cs, 131I), and total radiation, which is based on the information which is auto-recognized and interpolated for virtually measured radiation data by using random number generation. Especially, the radiation contour is displayed on the map image of the measured area so that the radiation distribution can be understood at a glance. 2D and 3D mapping programming for the distribution of radiation on the simulated measured radiation data was carried out by using MATLAB language. It showed the operation time of a few ten seconds which was more than 100 times faster than conventional technique. It was thought that the present study could be directly employed for the understanding of rapid and comprehensive radiation distribution on the public environment at the nuclear or radiation emergency