Abstract: Rural household biogas construction is a key program to current renewable energy construction in China. As daily-consumed energy for livelihood, biogas can substitute traditional biomass energy and provide clean energy for the rural residents, which can reduce the discharge of noxious gas, such as CO₂ and SO₂, and therefore partly moderate the tendency of the global warming. The quantity of emission reduction caused by household biogas construction substitution from 1996 to 2003 was analyzed according to international commonly used calculation method of emission reduction. The result showed that the use of biogas can reduce the discharge of CO₂ 397600 to 4 193900 ton and SO₂ 21 300 to 62000 ton. The emission reduction of CO₂ and SO₂ brought by the development of household biogas industry from 2010 to 2050 is forecasted. The rural household biogas construction of China is an effective measure to save energy, improve the efficiency of energy utilization, decrease the discharge of air pollution and lower the incidence rate of disease caused by poisonous gas.