Abstract: The basic data of traffic flow, vehicle type and vehicle speed of road network in Yangquan City were obtained through the simulation by van Aerde speed-traffic flow model and the traffic flow survey. Based on the actual road traffic flow data, vehicle emission factors and road sections, the emission inventory of motor vehicle of Yangquan City was constructed by using the bottom-up method, and the emission characteristics of vehicle exhaust were analyzed. The results showed that the emissions of CO, HC, NO_x and PM from the road vehicles in the city in 2017 was 4.56×10⁴, 0.96×10⁴, 1.76×10⁴ and 0.024×10⁴ t, respectively. According to road category, the highway (including urban expressway) was the main contributor of CO, HC, NO_x and PM, accounting for 48.4%, 48.9%, 40.0% and 34.3% of total emissions respectively. In terms of vehicle type, car was the main contributor of CO and HC emission and heavy truck was the main contributor of NO_x and PM emission. Based on emission stages, vehicles of national stage 4 emitted the main proportion of CO and HC, vehicles of national stage 3 emitted the highest proportion of NO_x and PM. In the view of geographical distribution, Yu County was the largest pollutants emission area, followed by Pingding County and suburbs. The research showed that the actual emissions of motor vehicles on the road were closely related to the road category, the administrative region of the road and the vehicle type.