OBJECTIVE： To determine the content of acetic acid in Octreotide acetate for injection by IEC，and provide reference for the improvement of pharmacopoeia standards. METHODS： The column was Rezex ROA-Organic Acid H+ with mobile phase of 0.002 5 mol/L sulfuric acid at a flow rate of 0.5 ml/min， the detection wavelength was 210 nm， column temperature was 45 ℃， and injection volume was 100 μl. RESULTS： The linear range of acetic acid was 0.394 4 μg/ml-78.89 μg/ml （r＝0.999 9）； RSDs of precision， stability and reproducibility tests were all lower than 2％； the limit of quantification was 197.2 ng/ml，and limit of detection was 78.89 ng/ml； recovery was 104.71％-109.78％（RSD＝1.34％， n＝9）. CONCLUSIONS： The method is environmental and simple with good accuracy and precision， and suitable for the content determination of acetic acid in Octreotide acetate for injection.