Elevated serum amylase is a common clinical syndrome which can be caused by a variety of causes. Hyperamylasemia is diagnosed as elevation of serum amylase level 3 or more times of upper limit of the normal value, and there are no obvious clinical symptoms such as upper abdominal pain. Hyperamylasemia can occur in a variety of diseases. Isozyme analysis can improve the specificity of diagnosis and has high diagnostic value. Clinically, the patients with hyperamylasemia shall be examined properly to make a definite diagnosis and symptomatic treatment as soon as possible.