Abstract： Objective To establish an ion chromatography to simultaneously determine acetate ion,chloride ion,sulfurous acid ion,sulfate ion and oxalate ion in low molecular weight heparin sodium injection.Methods The chromatographic column was Dionex IonPack AS11(250 mm×4 mm),and the protective column was Dionex IonPack AG11(50 mm × 4 mm).The automatic eluent generator and the gradient elution of potassium hydroxide were used.The flow rate was 1.0 mL·min-1.A conductivity detector was used with a chemical inhibitor.Results The method showed good linearity at 0.12～24 μg·mL-1 for acetate ion(r=0.9991),0.24～48 μg·mL-1 for chloride ion(r=0.9999),0.4～80 μg·mL-1 for sulfurous acid ion(r=0.9999),0.04～8 μg·mL-1 for sulfate ion(r=0.9995),and 0.3～60 μg·mL-1 for oxalate ion(r=0.9995),respectively.The average recoveries(n=6)were 105.3％(RSD=2.2％),101.0％(RSD=1.8％),102.3％(RSD=1.6％),96.8％(RSD=2.6％),and 108.3％(RSD=1.6％)for acetate ion,chloride ion,sulfurous acid ion,sulfate ion and oxalate ion,respectively.Conclusion The method is simple,sensitive and efficient,which can be used to simultaneously determine the content of acetate,sulfurous acid,sulfate,oxalate and chloride ions in low molecular weight heparin sodium injection,and to control its quality.