Abstract: Under laboratory conditions,the degradation characteristics of BaP and DBA in soils were studied.Four kinds of soil,loam soil from Shanghai,red soil from Jiangxi,black soil from Northeast China and Taihu Lake paddy soil from Jiangsu were used for the study.Results indicate that the degradation reaction of BaP and DBA was slow in the four soils.The organic matter content and pH of soils have an obvious influence on their degradation.When the added concentration of BaP and DBA was 2.5 mg·kg-1,BaP degraded quickly in the acidic Jiangxi red soil 125 days after the application,the degradation rate reached to 87.3%.DBA degraded quickly in the neutral Taihu Lake paddy soil,with high content of organic matter,the degradation rate reached to 52.0% 125 days after DBA application.The bio-degradation of BaP and DBA in the four soils was mainly induced by indigene micro-organism.Suitable C/N ratio speeded up BaP and DBA degradation.Aerobic condition is also favorable to such degradation.

Key words: PAHs, BaP, DBA, degradation in soil