Abstract: Since the reform and opening up in China, the transfer of rural surplus labor force has made great achievements but there were some difficulties that can not be ignored. From an objective perspective, at present there were a large number of rural surplus labor forces in China rural areas, who are not high quality, strong farmer’s mentality and monotonic diversion channels, resulting in so slow transfer process. In the study, it was firstly assumed that if the marginal revenue is different in various industries or trades, farmers seeking profit maximization will reach the better situation. The second, the surplus rate of agricultural labor force can be calculated by SPSS statistical software. The average wage of urban employment workers was regarded as the marginal revenue of non-agricultural labor force. The average wage of agriculture (forestry, animal husbandry, fisheries) workers was regarded as the marginal revenue of agricultural labor force in rural areas. The exponential function was used to fit the time series of the average wage. Finally, the agricultural surplus labor force was estimated and forecasted in China from 2012 to 2040.