An ultrasound-assisted ion chromatographic method was developed for the determinination of hexavalent chromium in the chromium contaminated sites.Using 0.3 mol/L KCl solution as extractant,12 soil samples were treated by ultrasonic assisted extraction for 20 min.The sample was analyzed on a Metrosep A Supp 4-250（250 mm×4.0 mm） anion separation column,using a mixture of 4 mmol/L Na2CO3-1 mmol/L NaHCO3 as eluent.The method showed a good linearity（r2=0.999 8） in the range of 0.01-20 mg/L for the hexavalent chromium.The detection limit was 0.003 mg/L,the spiked recoveries were in the range of 96.4%-106.8% with RSDs（n=3） of 0.56%.The method was simple,rapid and accurate,and was suitable for the investigation on the chromium contaminated sites.