ABSTRACTPolycyclic aromatic hydrocarbons (PAHs) occur in the surface water of the Taizi River, China. The levels and composition patterns were studied by high-performance liquid chromatography and PAHs sources were analyzed using the isomer ratios of selected PAH compounds. In the flood period, concentrations of PAHs ranged from 1562.52 to 4176.15 ng/L with a mean of 2562.56 ng/L. In the dry period, concentrations ranged from 498.09 to 3218.27 ng/L with a mean of 1389.30 ng/L. The levels of ΣPAHs in the study area were higher than in other locations. The dominant PAHs were Baa in the flood period and Phe, Flu and Pyr in the dry period. The composition of PAHs was dominated by four-ring PAHs (51.72–82.69%) in the flood period and three-ring (28.25–50.10%) and four-ring PAHs (38.28–56.28%) in the dry period. The isomer ratios of Ant/(Ant + Phe), Flu/(Flu + Pyr) and compositional analysis were selected to identify the sources of PAHs. Coal combustion and traffic emission were the sources of PAHs in the surface water of the Taizi River, and the major source of PAHs was from combustion of coal.