Japan is a nation in which natural disasters, including landslide, floods, debris flow, and soil erosion, occur frequently every year. The government has paid much attention to controlling the natural disasters since the end of World War Two. As a result, there was also a great progress in research dealing with natural disaster during this period. In this paper, the universities and authorizations dealing with water and soil conservation, as well as main leading researchers in Japan are introduced, the history and characteristics of soil erosion and conservation studies, as well as some important results up to now are systematically evaluated.