Abstract: Life cycle assessment was performed for a biodiesel made from rapeseed. A risk evaluation model of chemical pollutants include the index of greenhouse gas, acid gas and particulate matter. The results show that the index of greenhouse gas the index of acid gas and the index of particulate matter are 0.71, 1.61, 1.17, respectively. Namely greenhouse gas, acid gas and particulate matter emissions of biodiesel are 0.71 times, 1.61 times and 5.87 times that of petrochemical diesel. Biodiesel emissions of greenhouse gas is dominated by CO2, emissions account for 93.42 % of the total amount of greenhouse gas; acid gas mainly to NOX, emissions account for 74.08 % of the total amount of acid gas.In the production process of biodiesel, acid gas and particulate matter emissions is the greatest, i.e., 75.20 % and 74.13 % of total emissions, respectively. In the process of using biodiesel, greenhouse gas emissions is the largest and accounts for 46.89 % of total emissions. A kind of effective measures to reduce chemical pollutant emissions of biodiesel is to reduce the use of coal and other materials, and develope clean and efficient production process.