Abstract: To learn the pollution characteristics and source of PAHs in Dalian sea, 16 polycyclic aromatic hydrocarbons(PAHs) were analyzed in surface sediment samples collected from coastal. The results showed that the concentration of 16PAHs was 30.0410-9~89.2410-9 with the mean value of 50.8410-9.The concentrations of PAHs in industrial districts were higher significantly than those in urban(p0.05) and rural districts(p0.01).Significantly positive correlation between PAHs and TOC(p0.05) implied that the organic content was one important factor affecting the concentration of PAHs in sediment. The results of sources of PAHs analysis showed that the sources of PAHs were from crude oil, fossil and biomass burning and diesel fuel.