Abstract: Since the year of 2004, the production cost of China's staple crops has increased rapidly and the cost advantages of some staple grain producing provinces tend to be weakened or even turned into disadvantages, which brings a negative impact on grain production benefit, farmers' income growth and food security. Based on the method of decomposition of factor cost contribution, this paper empirically analyzes the source of the rapid increase of the production costs of classified China's staple crops at both national and provincial level. The results show that, in terms of the average cost of the staple crops at the national level, the labor cost is the factor cost with the highest contribution to the increase of total production costs, while the labor price, especially in the opportunity cost of family self-employment is the main driving force for the continuous increase of labor cost and the total costs of grain production. However, due to different input structures of various staple grains factor as well as different grain production modes and conditions in different regions, there exist inter-crops and inter-provincial differences in the structure of factor cost contribution. In terms of different crops and different major producing provinces, the primary and secondary causes of the rising costs of staple crops production are not the same.

Key words: staple crops production cost, decomposition of factor cost contribution, labor cost