Abstract: Carbon emission from different agricultural activities (e.g., fertilizers, pesticides, agricultural films, irrigation, tilling and diesel utilization) in Hunan Province during the periods of 1999-2014 were calculated. Its relationship with agricultural economy was further investigated using the environmental Kuznets curve model. The carbon emission and agricultural economy in Hunan Province represented several decoupling relationships between them, such as significantly negative, weak and weakly negative decoupling relationships. The data indicated a trend of "rapid growth phase—rapid descent phase—stationary phase" between the carbon emission and agricultural economy. In addition, the amounts and intensity of carbon emission significantly increased (a logarithmic growth mode) with a sustainable development of agricultural economy. The results suggest that the agricultural development in Hunan Province faces several key problems, such as high resource consuming, low efficiency of resource utilization and negative effects on the environment.