Abstract: The concentration, distribution and transfer of dichloro-diphenyl-tricgloroethanes(DDTs) in the surface layer water, sediments and aquatic organisms from the Zhangjiang River Estuary were investigated using GC-ECD method. The possible sources were assessed based on the distribution and composition characteristics of DDTs together with the investigation results of dicofol. The results showed that the concentration of DDTs in surface layer water ranged from ND (not detected) to 20.1 ng·L^-1 with an average of 10.5 ng·L^-1 in dry period, from ND to 45.2 ng·L^-1 with an average of 28.3 ng·L^-1 in wet period, and from ND to 18.8 ng·L^-1 with an average of 5.03 ng·L^-1 in level period. Concentration of DDTs in surface sediment (dry mass) ranged from 1.87 ng·g^-1 to 144 ng·g^-1 with an average of 17.3 ng·g^-1, and that in 11 species of aquatic organisms ranged from 1.09 ng·g^-1 to 432 ng·g^-1 with an average of 37.0 ng·g^-1. Compared to other areas, the residues of DDTs in the Zhangjiang River Estuary were at the medium level. The accumulation factors of DDTs in sediment and aquatic organisms were 1185 and 2534, respectively. The capacities for DDTs accumulation were in the order of fish>shellfish>shrimp>aquatic plants. The concentrations of DDTs showed downtrend along the Zhangjiang River, indicating that the residues of DDTs mainly came from terrigenous pollution rather than from the release of antifouling agent of ships. Based on the composition profile, DDTs mainly came from the early residues. However, the highest value of dicofol was recently detected both in the water and sediment of Y-8 station, which suggested that new DDTs inputs at the Y-8 station might be related to the recent usage of dicofol.