Abstract: It is shown that organic contaminative grade in 1998 is 1.36 to 4.36 times than 1995 by analyzing PAHs in aerosols at Macao in 1995 and 1998 . It is suggested thatPAHs concentrations in aerosols at day are higher than those at night , with day and night diversity of resident emitting from working ,living ,commerce and traffic .It is believedthat commercial and traffic function areas are serious pollution sites because the concentrations of benzo( a) pyrene and benzo( a) anthracene are 1.56～8.10ng/m3 and 0.85～4.68ng/m3 in aerosols ,respectively .