Based on spatial and temporal disparities of technology level and production intensification level and such key data as growth circle of different breeding patterns and quantity,this paper calculates the amount of greenhouse gas emission in pig breeding.The result shows that carbon emission rises by shock trend,increasing from 108 million t CO2 equivalent in 1998 to 133 million t CO2 equivalent in 2015.Intensive pig farms have become the main contributor to carbon emission,whose gas emission reached 73.57% in 2015.Sichuan,Hunan,Henan,and Shandong provinces are the largest producers of carbon emission among all provinces.Furthermore,a LMDI decomposition model shows that expansion of pig production is the main driving force in the growth of carbon emission,which pushes forward the growth rate of carbon emission to 43.93%.Technology progress and production intensification has cut nearly half of the carbon emission.Therefore,improving breeding technology,promoting production intensification and treating feces with biogas digesters are the important measures to reduce carbon emission of greenhouse gas.