Glutamyl transpeptidase is a routine test in the liver enzyme profile and is normally found in liver, pancreas and kidney tissues. The test of this enzyme can reflect the pathology of these organs, especially in liver diseases, and is important for the differential diagnosis of some diseases. The normal range of glutamyl transpeptidase in blood is 3-50U/L, and there is no clinical statement that glutamyl transpeptidase is low. Of course, the lower limit of normal value of glutamyl transpeptidase may not be 3U/L, sometimes it is set to 4U/L, sometimes it is set to 8U/L. The value of glutamyl transpeptidase may be lower than the lower limit of normal value, but it is not necessarily clinically significant and clinical treatment is not necessary at this time. Therefore, when glutamyl transpeptidase is detected less than 10U/L, there is no need to worry, it is generally normal. However, when glutamyl transpeptidase is elevated, the cause should be actively investigated. Mild elevation may be caused by physiological factors, such as alcohol consumption, overexertion, etc. In case of moderate elevation, it may be caused by liver diseases such as acute or chronic hepatitis or cirrhosis. If there is a significant elevation, it is likely to be caused by alcoholic liver disease, primary liver cancer, and biliary obstructive disease. Therefore, when this index is found to be elevated, it should be combined with other imaging and laboratory tests for further clarification, and targeted treatment is needed for different causes.