Agricultural production is critical for carbon budget of arable land and global climate change. With the economic and social development after the founding of new China, there are a lot of changes on the mode of agricultural production and the way of arable land utilization, such as rapid reduction of ecological land use, great expansion of reclamation area and remarkable increase of grain output. Those changes have made a strong impact on carbon budget of China. Based on the related statistics of agricultural production from 1949 to 2006, this paper profoundly analyzed the change of carbon emission and carbon sink during grain production in these almost 60 years according to the change of arable land area in these years. As considering irrational agricultural production mode is the critical factor which made the great increase of carbon emission in agricultural production, this paper believed only promoting the transition of agricultural production mode is able to radically solve the problem of carbon emission in grain production of China on the prediction of ensuring food security and arable land area. Based on above analysis, this paper also put forward some helpful policy suggestions on developing low-carbon agriculture.