Abstract: The pollutant emission characteristics and driving characteristics of vehicles in city of Urumqi，the capital of Xinjiang Uygur Autonomous Ｒegion were analyzed by the data got on the selected 125 roads in the city． And then COPEＲT model was used to calculate the emission factor of CO，NMVOC，NOx and PM; the emission of CO，NMVOC，NOx and PM were 94 087，17 886，25 079 and 1 489 t in 2012，respectively． Passenger cars were the major exhausting parts of CO and NMVOC． Heavy truck contributes most to NOx emissions，and heavy truck，light truck and passenger car were also the PM main contributors． The NOx and PM contribution proportion of diesel vehicle were greatly larger than its quantities proportion， while the CO and NMVOC emission contribution proportion was less than its quantities proportion． The pre—EuroⅠand Euro Ⅰvehicles significantly contributed to total CO，NMVOC，NOx and PM emission，with the contribution proportion 50. 5%， 41. 0%，51. 5% and 55. 0% respectively，while its quantities were about 22. 3% of the total． In contrast，the CO，NMVOC， NOx and PM emissions of Euro Ⅲ and EuroⅣvehicles were 35. 2%、42. 7%、35. 6% and 33. 9% respectively． So measures of controlling vehicle pollutants should focus on the pre-EuroⅠand EuroⅠ．