This research suggest the viewshed frequency concept to improve the limit of viewshed analysis and realized it through the programming. Viewshed frequency analysis presents arithmetic operation for several results of multilayered observation points, and designed for not only one building but also large scale of research sites. The results of research were as followed: (1) Viewshed frequency analysis makes possible multi viewpoints stereoscopic analysis and showed more improved results. (2) Viewshed frequency analysis has no limits of the scale of research sites by multi-layered grid observation points method. (3) Viewshed frequency analysis has more elaborate result with DEM which has building height and NDVI(Normalized Difference Vegetation Index).