Abstract: Seven anions,i.e.,F-,Cl-,NO-2,Br-,NO-3,PO3-4 and SO2-4,in environmental water were determined by HPLC,with Asahipak ODP-50 (4.0 mm×150 mm,5 μm) column at 40 ℃ as the stationary phase and a mixed solution containing phthalate additive,acetonitrile and water mixed in the ratio of 5 to 14 to 81 diode array detector by volume as the mobile phase at flow-rate of 1.5 mL·min-1.UV-detection at 266 nm with diode array detector (DAD) was applied to the determination.Linear relationships between values of peak area and concentration of the 7 anions were obtained with correlation coefficients ranging from 0.999 8 to 0.999 9.Detection limits (S/N=3) for the 7 anions found were 8,14,34,59,37,30 and 80 μg·L-1 respectively.Precision of the method was tested,giving values of RSD′s (n=6)≤2.0%.Tests for recovery were made by standard addition method,the results obtained were in the range of 95.3%-98.6%.The proposed method has been applied to the analysis of samples of surface water,ground water,mineral water,drinking water and waste water.