A method for the determination of HCHs and DDTs in fish by isopropanol-K_2HPO_4-H_2 O aqueous two-phase extraction and gas chromatography was established The method investigates the effects of isopropanol alcohol aqueous solution volume fraction and decontaminants on extraction ratio of HCHs and DDTs. The HCHs showed good linearity in range of 0. 50 ~ 100 μg/L,and the DDTs showed good linearity in range of 1. 00 ~ 100 μg/L. The average recovery rate of HCHs and DDTs ranges from 78. 6% ~ 104. 2% and the limi...