With the advancement of urbanization and industrialization in China， a large number of agricultural labor forces have transferred， providing an important driving force for the continued economic growth.However， rising labor costs may have a negative impact on agricultural total factor productivity.From the perspective of factor substitution， areas and crops where machinery is difficult to replace labor should be more affected by the increase in labor prices.This article studies the above issues based on unbalanced panel data of 2463 counties in China from 1993 to 2015.The empirical results indicate that rising labor costs do have a significant negative impact on China's agricultural total factor productivity.In order to characterize factor substitution， especially the role of machinery substituting for labor， this article explores the effects of different slopes and different crops.The empirical results show that， on the one hand， in areas with a high proportion of sloping farmland， it is more difficult for machinery to replace labor， resulting in a greater negative impact on agricultural total factor productivity.On the other hand， compared with food crops， it is more difficult for machinery to replace labor in the production of cash crops.Therefore， rising labor costs will lead to a grain-oriented planting structure.Considering that cash crops are relatively efficient， this will lead to the overall decline in agricultural total factor productivity.