Abstract: Atmospheric particulate matter samples were collected at Pingtan Island over the western Taiwan Straitregion from January to April,2006.Polychlorinated biphenyls(PCRs)of the samples were analyzed by Gas chm-matography Electron capture detector(GCECD),and then the concentrations,compositions,possible sources ofPCBs and dioxin-like polychlorinated biphenyls(DL-PCBs)were studied.Results showed that the mass concentra-tions of PCBs in the Pingtan Island aerosol samples varied from 0.223 pg/m³to 21.658 pg/m³,with an average of 4.820 pg/m³.PCB138 and PCB189 were the major homolog monomers of the 28 analyzed PCBs'homolog mono-mers.Higher molecular weight PCB congeners were dominated and the average ratios of concentrations for hexa-and hepta-CBs to the total PCBs concentrations were 44.5%and 32.2%respectively.The toxic equivalent quanti-ties(TEQ)of 11 DLPCBs were in the range of 0.008~215.576 fg/m³,whilePCBI26,PCB 123and PCB 189were the dominant contributors to the TEQ.Concentrations of Crm-z and CMLPc-Awere higher in winter(Januaryand February),while alittle lower in spring(March and April).Backward air mass trajectory analysis suggestedthat heating and industrial emissions of northem urban areas in China may contribute some PCBs pollution to Ping-tan Island in winter and spring.