Aging and bioavailability of DDTs in paddy soil were investigated in the lab under simulated conditions.Results indicate that aging phenomena of DDTs existed in soil.Extractable DDTs decreased as the time elapsed.Its aging rate was rather high at the initial stage,and then slowed down in the rest of the time.During the first 30 days,o,p'2DDT,p,p'2DDT,o,p'-DDE,p,p'2DDE and p,p'2DDD dropped by 53.5% ,52.1% ,31.4% ,36.0% and 38.3% ,respectively due to high aging rate.DDTs,bioaccumulated in earthworm displayed the same rule as aging,that is,the contents of DDTs in earthworm decreased as the incubation time extended and so did.Bioconcentration factors(BCF)of DDTs in earthworm show a decreasing order of BCF_p,p'2DDE>BCF_p,p'2DDD>BCF_o,p'2DDE>BCF_o,p'2DDT>BCF_p,p'2DDT.Though the extractable DDTs decreased with aging, they still accumulated in earthworms through bioconcentration,and biomagnified through the food chain,thus posing potential environmental risk.