The present situation of vegetation and desertification is reported. The natural factor of desertification is diversity and imbalance of soil condition and vegetation caused by earth meteorology and topography. Additionally, as human factor, the population expansion and land-use for agricultural production is discussed. Because of limitation of nature world to the development of species, gene operation, soil improvement, the reformation of human factor is very necessary. On the contrary, dispersal and appeasement of l pressure to soil by introducing reform of agricultural land-use system and method could only contribute the improvement of effectiveness. Therefore, fundamentally, the reguration and control of population must be necessary as a result of ecological science with quantitative analysis of Homo sapience population. By the present moral and legal situation of human society, introduce of population planning by pre-birth could be necessary for population control. With the quantitative analysis of situation of each environmental factors, poputation regulation at lowering environment area and conservation of natural resources and surplus production at high environment area by also population reguration, and resource apportion to lowering area by high area could be promoted. For those social system-making, knowledge and technology of ecological scientist would contribute realistically.