This Standard is formulated for the purpose of implementing the Environmental Protection Law of the People's Republic of China and the Law of the People's Republic of China and Law of the People's Republic of China on the Prevention and Control of Atmospheric Pollution, preventing and controlling the pollution by emissions of pollutants from mopeds and improving ambient air quality. The current Standard specifies the limits and measurement methods for the emissions of pollutants from motorcycles on the running mode, crankcase emission requirement and durability requirements for pollution control devices. It presents the approval requirement, production consistency check and identification method for mopeds on the running mode (CHINA stage Ⅲ). The current Standard is applicable to the two-wheel or three-wheel mopeds with total mass less than 400kg, designed maximum speed less than 50km/h with the ignition engine with emission volume less than 50mL. It will be put into effect as of July 1, 2008 and replace GB 14622-2002 from then on.