Abstract: The conclusions,by studying on the characteristics of the concentrations of priority polycyclic aromatic hydrocarbons in dustfall and contrasting with aerosols in Macao,are as follows.①The concentrations of priority PAHs in dustfall were influenced by spatial locations and were diluted by soil from ground,and the highest concentrations were occurred at heavy traffic,commercial and crowded residents region.②The concentrations of priority PAHs in dustfall are lower than those in aerosol,and the ratios of the concentrations of priority PAHs in dustfall to those in aerosol are 0 02 to 0 08 at night and 0 03 to 0 12 in daytime,respectively.③There is a difference in the distrbution of individual priority PAHs in dustfall and in aerosol,scarce of 2-ring and 3-ring compounds of PAHs in aerosol and rich in 4-ring compounds of PAHs in dustfall.