Whether aminotransferase 300U/L affects life expectancy cannot be determined, aminotransferase 300U/L indicates liver function impairment, which may affect life expectancy if it is caused by cirrhosis or hepatocellular carcinoma. Transaminase 300U/L level is relatively high, most of them are not caused by physiological factors, because physiological factors caused by only mildly high transaminase, often because of liver function abnormalities caused by disease, if it is caused by serious liver diseases such as cirrhosis or liver cancer, the treatment is more difficult, and often affects the patient’s life expectancy. However, it may also be caused by benign diseases such as viral hepatitis, fatty liver, cholecystitis. After active treatment, the transaminases will usually return to normal and will not affect life expectancy. When the transaminase is 300U/L, it is necessary to cooperate with the doctor to do further examination, clear diagnosis and timely treatment.