OBJECTIVE:To provide reference for the understanding of quality status of Insulin injection and improvement of related standards. METHODS:The statutory methods of Insulin injection were adopted to test 32 batches of samples(including ap-pearance,identification,capacity,visible foreign matter,sterility and potency determination of biological method). Consulting specification of other similar products,RP-HPLC was conducted to determine the related impurities,content and phenol in sam-ples;HPSEC was conducted to determine the high molecular weight proteins and atomic absorption spectrophotometry was conduct-ed to determine the Zn content. RESULTS:Results of all the 32 batches of samples were qualified by the test of statutory methods. According to the method of other similar products,the determination result of A21 desamido insulin was 15.6%-39.2% and general-ly greater than 5.0%, which was the highest limit of similar products;insulin was 93.2%-102.7%;protein polymer was 0.5%-0.6%;phenol was 2.34-2.51 mg/ml and Zn was 12.3-14.8 μg/100 U. CONCLUSIONS:The statutory specification of Insulin injection is short of many key specification items such as impurities and content determination;the contents of protein polymer, phenol and Zn were in good control;the contents of A21 desamido insulin are generally high,and stability of insulin main peak is relatively poor.