Contents of Pb2+ and Ni2+ in soy sauce were determined by the online derivation and HPLC method with wet digestion.Sodium diethyldithiocarbamate（NaDDTC） was used as the derivtive agent for heavy metal ions.The experimental conditions were as follows：chromatography column:a Hypersil ODS2 C-18（5 μm,250 mm×4.6 mm） column，mobile phase：MeOH-H2O-sodium diethyldithiocarbamate（63.5∶35∶1.5）.The calibration curves for Pb2+ and Ni2+ were linear in the range of 0.5-50 μg/mL with correlation coefficients of 0.998 2 and 0.999 0，respectively.The limits of detection were 0.3 μg/mL and 0.2 μg/mL，respectively，with recoveries of 88.1%-91.8%.The method has the advantages of simplicity，good accuracy and precision，and could be used as an alternative method for the determination of heavy metal ions in real soy sauce samples.