How about the future trends of cultivated area change in China? Figures provided by some materials differ from each other dramatically. In this paper, We discuss the relationship of the decrease of cultivated area with many variables such as total population, urban population, rural population, gross domestic products, primary industry growth, secondary industry growth and tertiary industry growth, et.. It is proved that the decrease of cultivated area is intensively related to population growth and economic development and that the urbanizition not only dosen’t aggravate the decrease of cultivated area but also do economize on cultivated area. Our forecast is that the cultivated area of China will decrease to 10.741￣10.831 million hectares by 2035 when the population peak is reached, which compared to 12. 8 million hedtares in 1985 decrease by 7.8%, and return to 10939￣10969 million hectares in 2050 because of the decrease of total population and growth of urbanizition level.