Abstract: Polycyclic aromatic hydrocarbons (PAHs) in water column from Macau coastal waters are analyzed quantitatively.The preliminary results are as follows:The mass concentrations of total PAHs (dissolved and particulate phase) are from 1 854.4 to 8 733.4 ng/L,and those of PAHs in dissolved and particulate phase range from 892 to 7 944.5 ng/L and from 339.4 to 969.5 ng/L respectively.The levels of 16 PAHs in Macau coastal waters range between 940 and 6 654 ng/L.The mass concentrations of PAHs in particulate phase and the partition coefficients (lg K_p) of PAHs between particulate phase and dissolved phase are decreasing with the increase of depth,indicating the predominant deposition process and horizontal transportation for particles in water column.The relative high lg K_p values are found for PAHs in deeper water samples,suggesting the increase of suspended particle matters and the intrusion of salt water.