Abstract: Life cycle assessment is used to analyze the fuel cell vehicles using different hydrogen sources.After goal and scope definition,inventory analysis,impact assessment and interpretation,it is showed that the emitted pollutants of vehicles using hydrogen produced by water electrolyzer are more than those of methanol reformer vehicles and gasoline reformer vehicles,and the emitted pollutants of methanol reformer vehicles and gasoline reformer vehicles are more than those of vehicles using hydrogen produced by natural gas reformer or coal gasification.For vehicles using the same hydrogen production method,the study showed that the emitted pollutants of liquid hydrogen method are a little more than those of gas hydrogen method.