Objective: A high performance liquid chromatography method was developed to determine EDTA and NTA in water. Methods: The samples were derivatized with ferric chloride, used methanol and a 0.2 mmol/L tetrabutylammonium bromide phosphate buffer solution (pH 2.5) as the mobile phase, separated on a Thermo-C₁₈ (4.6 mm×250 mm) column after gradient elution, detected by HPLC with a diode array detector, and used external standard method for quantitation. Results: The content of EDTA and NTA showed a good linear relationship in the range of 0.1～2.0 mg/L, the correlation coefficients were 0.999 5 and 0.999 2 respectively; The limits of detection were 0.05 mg/L and limits of quantification were 0.1 mg/L; The average recoveries were 93.5%～111.4%; And the relative standard deviations (RSD) were 3.63%～7.39%. Conclusion: This method was convenient, repeatable, sensitive, and practical for the detection of EDTA and NTA.