From the point of view of economic theory and the reality of China, with Lewis turning point of labor transfer trend, this paper reestimates the agricultural labor force and its rate, and the problem of rural labor force transfer. The results show that, the proportion of agricultural labor should fall into that of the same average per capita income countries which is about 14%, and on the basis of 2012, down 0.75 percentage points a year when a well-off society in 2020 is built. At the same time, on the basis of the urbanization rate of 52.6% in 2012, the proportion of agricultural labor should increase by 0.9 percentage points a year, reaching 60% in 2020. <<