Aiming at the technologies of sweet sorghum planting and advanced solid state fermentation (ASSF) in Inner Mongolia, a life cycle assessment (LCA) model on energy consumption, greenhouse gas emissions and other relative impact factors was established together with a database of fertilizer, pesticide and other energy inputs. The model showed that the energy input was 34831MJ/t and mainly distributed in sweet sorghum planting and ethanol producing phases. The energy output, net energy produced, energymaking efficiency and CO2 emissions were 46562MJ/t, 11730.97MJ/t, 1.34 and 93.23g/MJ, respectively. The results showed sweet sorghum ethanol making was feasible from the view point of energy production. 