The normal value of alanine aminotransferase is 0-40U/L. The so-called low value refers to the relative low value within the normal range, which has no special significance for people without obvious liver diseases, but if there are liver diseases, the relative low value of this index may be something. 1. No special significance: alanine aminotransferase belongs to the liver function index, when the index is elevated, it suggests that there is destruction of liver cells and liver function is damaged. For people who do not have obvious liver disease, the low value of alanine aminotransferase belongs to the normal range of relatively low, normal phenomenon, usually does not indicate whether there is something wrong or not, and has no special clinical significance. Meanwhile, the low value may also be caused by measurement error. 2. When there are obvious liver diseases, such as severe viral hepatitis and liver failure, it will cause a lot of liver cell destruction and liver cells can not be regenerated, then the phenomenon of low alanine aminotransferase will occur, and at this time there is something wrong and the situation is more serious and dangerous. Alanine aminotransferase relatively low is best for observation, if there is discomfort in time to consult the doctor, identify the causes of active treatment, so as not to delay the condition.