Abstract: On the basis of analytical results of mass concentrations and major compositons of TSP,PM₁₀ ,PM_2.5 obtained around Tanyugou highway tunnel,the average emission factors and mass concentrations of major compositions of particles with different diameters from traffic under certain vehicle flow rates and vehicle velocities were obtained.These emission factors could basically represent the comprehensive emission factors of particles from vehicle traffic in Beijing.It is also practical for calculation and modeling of vehicle emission pollution.The emission amounts of particles with different diameters and their major chemical components from traffic sources in Beijing were calculated also.