Cholinesterase is an indicator of liver function test, and the normal range is 4.3-10.5 U/L. The normal range varies in different hospitals due to different testing methods, reagents and instruments, for example, the normal range of cholinesterase measured by colorimetric assay may be 130-310 U/L. Since serum cholinesterase is synthesized by the liver, the activity of cholinesterase reflects the condition of the liver, especially when the activity is decreased, it indicates liver damage. the condition of the liver, especially when cholinesterase activity is decreased, indicating liver damage. For example, in acute viral hepatitis, the degree of serum cholinesterase reduction in patients correlates with the severity of the disease, and a persistent decline in serum cholinesterase often indicates a poor prognosis. Cholinesterase can also be used as one of the indicators for determining the stage of cirrhosis, for example, in compensated cirrhosis, serum cholinesterase is mostly normal, and in decompensated cirrhosis, serum cholinesterase will show a significant decrease. Patients with extrahepatic bile duct obstruction should also be alerted to the presence of biliary cirrhosis if there is a significant decrease in serum cholinesterase.