Distribution of polycyclic aromatic hydrocarbons (PAHs) among soil organic matter pools different in activity may influence their mobility and bioavailability in the soil.In this research,the distribution characteristics of 15 kinds of USEPA priority PAHs in soil light fractions,heavy fractions and different fract ions of combined humus of soil heavy fractions were studied by the fractionation method for soil organo mineral complexes.The results showed that the contents of total PAHs in light fractions ranged from 1.30 10⁴ to 1.07 10⁵g kg^-1,far greater than in heavy fractions,ranging from 221.7 to 297.8 g kg^-1,Al though the light fractions accounted for only 0.4% to 2.3% of the soil,they got associated with 31.5% to 69.5% of the PAHs in soils.The PAHs in heavy fract ions were mainly associated with tightly combined humus,account ing for 71.2% to 87.2% of total PAHs in heavy fraction.The contents of PAHs in different fractions of combined humus of heavy fractions had significantly positive correlation with their organic carbon contents (p<0.01),The enrichment ability of tightly combined humus was signifi cantly greater than that of stably combined and loosely combined humus.Environmental risk of PAHs polluted soils probably comes mainly from the PAHs combined with soil light fractions.