The aim is to determine anion content of groundwater, the ion-chromatography method was taken to detect common anion content in the sample of groundwater. The chromatographic condition was optimized. The optimum chromatographic condition is that ICS-1500 ion-chromatograph, SA_23-25 anion partition column and ASRA renewable suppressor are used with 4.5mmol/L Na2CO3 and 8.0 mmol/L NaHCO3 as eluent solution at 1.0 ml/min flow rate, using inhibitory electrical conductivity detector to detect 5 anions such as F-, Cl-, NO-3, PO43- and SO42- in groundwater sample. 4 anions were detected in water sample at three sites except PO43-, but the concentration value is in the field of standard. The method has good correlation（r>0.999）.The low detection limit is 0.02~0.12 mg/L,the accuracy is high (RSD 0.33%~3.07%). The paper set up the method which measures anions in groundwater with ion-chromatography in the meantime.