Abstract: The distribution characteristics of trace gases such as SO2, NO2 and O3, observed at Lin’an background station in the period from the last 10 days of August to the first 10 days of November, 1991, and the impact of the chemical transferring of these gases on the aerosol concentrations are investigated in the paper. The impact of air parcel trajectories and wind directions on the transfer process is also discussed. The results show that the concentrations of trace gases at this station are in existence of a remarkable diurnal variation under certain conditions, and the variation has an effect on the distributions of aerosol concentrations.