Four-year (1998--2001) data sets of chemical species in particulate matter of 10 ¿m in diameter or less (PM10) from a monitoring site in a south China coastal city, Hong Kong, comprising major crustal, marine, and anthropogenic species have been analyzed with respect to synoptic-scale and mesoscale meteorological patterns. Their relationships are discussed using surface pressure maps, back trajectory analysis, chemical transport modeling results, and other relevant meteorological data. The mean concentrations of K+, non-sea-salt sulfate (nss-SO42-), and NO3- in aerosols differed from that at a background site by no more than 15%, exemplifying the contributions of major sources from outside Hong Kong. Continental air masses associated with the East Asian winter monsoon always contain high contents of mineral dust and anthropogenic species such as nss-SO42- when they pass over the desert/loess areas and urban cities/heavy industrial areas of mainland China before reaching Hong Kong. Clear decreasing temporal trends of the concentrations of the anthropogenic species nss-SO42- and NO3- are evident during the sampling period. Emissions from biofuel combustion are mixed with urban/industrial plumes before reaching Hong Kong. Wet scavenging significantly depletes the concentrations of chemical species. Marine air masses associated with the summer monsoon or high-pressure systems near Japan always contain large amounts of sea-salt species, but there are noticeably different concentrations of crustal and anthropogenic species between these two weather patterns. The species K+, as a tracer for biomass burning, approaches background levels for summer monsoon air masses originating from Southeast Asia. The proximity and the arrival of the tropical cyclone reflect two extremes (very high/low) species levels. Stagnant air is not the only factor to govern the elevated species levels in aerosols, but the nature of air masses affecting Hong Kong before sampling should also be taken into consideration.