Different types of motor vehicles’ contribution rates of TSP and PM10 in second fugitive dust on urban road were analysed quantitatively.Concentration of TSP,concentration of PM10,pressure,temperature,wind speed,traffic volume of different types of motor vehicles and other informations were collected in some sections of Jungong Road in Shanghai city.Gaussian atmospheric diffusion model was used to identify reversely the source intensities of pollutions as well as the average motor vehicle emission factor.With multivariate regression method,it can be seen smalltype motor vehicle’s both pollutions contribution rates are negative,while middletype motor vehicle’s and largetype motor vehicle’s are positive,and the latter one is ones are respectively 1.74 times and 1.56 times as great as the former one.