Abstract: In this paper,the populations and emission factors of vehicles with different emission standards were obtained by abundant literature investigation and sampling survey.Then vehicular emission inventory was developed for the Beijing-Tianjin-Hebei(BTH) region in 2008,and emission characteristics were analysed at the same time.The results indicated that total emissions of CO,NO_x,HC and PM₁₀ were 264.05×104,78.79×104,63.09×104 and 4.83×104 t/a,respectively.Vehicles with State 0 standard were the major emission source,and the emission proportions for CO,NO_x,HC and PM₁₀ were 56.74%,35.51%,47.55% and 45.90%,respectively.The two major contributors to CO and HC were motorcycles and light duty vehicles.CO from these two types accounts for 40.92% and 35.43%,and HC accounts for 55.18% and 28.33% of the total vehicular emission respectively.Heavy duty trucks,heavy duty vehicles and trails were the main contribution sources of NO_x and PM₁₀.They made significant contribution about 88.59% to the total NOx emissions,while 75.10% to the total PM10 emissions.Beijing had lower average emission for a single car than the other cities in the BTH.Characteristics of cites' average CO and HC emission were similar with each other,so did NO_x and PM₁₀.