Polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) in a typical farmland soil from Yangtze River Delta region were detected by high resolution gas chromatography coupled with high resolution mass spectrometry(HRGC/HRMS).The results showed that averaged total PCDD/Fs concentration in the farmland soil was 2 639 pg g^-1 dw.The isomers of PCDD/Fs covered Cl₄~Cl₈.WHO-TEQ calculation indicated that PCDD/Fs TEQ in the soils ranged from 20.82 to 21.32 pg g^-1 dw,among which 2,3,4,7,8-PCDF and 1,2,3,7,8-PCDD were the two important isomers contributing largely to the total PCDD/Fs TEQ.It is concluded that the farmland soil had been contaminated to some extent with polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs) that were likely released from dismantlement,dissolution and cineration of capacitors in transformer and/or electronic wastes.