Abstract:The contents of 15 priority polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM) andsediment from six sampling sites in Lake Small Baiyangdian nearby Duancun Village were measured by GC-MS. The PAHsdistribution, composition, source and ecological risk were analyzed. The following results were obtained: (1) the total contents of 15priority PAHs (PAH15) varied from 40.1 to 74.0ng/L with the average of 51.0ng/L in water, from 2438.0 to 5927.0ng/g with theaverage of 4528ng/g in SPM, and from 466.9 to 1366.4ng/g with the average of 755.6ng/g in sediments. Compared with other areasin or out of China, the PAHs contamination was not serious. (2) The percentages of 2- and 3-rings PAHs accounted for more than80% of PAH15 in water, SPM and sediment, respectively. From water, SPM, to sediments, the percentages of 2-rings PAHs weredeclined sequentially; while these of 3- and 4-rings as well as 5- and 6-rings PAHs were increased gradually. (3) The major sources ofPAHs in sediments were the combustions of biomass fuels (straw, firewood) and coal; while the combustions of liquid fossil fuelsincluding gasoline, diesel and crude oil was the secondary sources. (4) Owing to the contents of Fluorene (FLO) and Phenanthrene(PHE) varying between the ERL(effects range low) and ERM (effects range median), their probabilities of ecological risks wasestimated between 10%-50%. The probabilities of ecological risks for the rest species of 15 priority PAHs were below 10%, sincetheir contents were lower than the ERL.