The clinical features of patients with macroamylasemia are diverse. A certain correlation between macroamylasemia and the disease of the pancreas or hepato-biliary system may exist, because among 7 patients in this series 4 patients were diagnosed as acute pancreatitis or relapsing pancreatitis and another patient was performed choledochotomy and manipulation of papilla of Vater may had a effect on pancreas. Among other 2 patients, one was completely symptomless and had no abnormal findings and in another the action of anticancer drugs is suspected. The course of macroamylasemia is usually chronic but in this series one patient had acute transient macroamylasemia and another one had intermittent macroamylasemia during exacerbations of pancreatitis. The serum amylase levels are mostly 2-4 times above normal with one exception (192 Somogyi units) and urinary amylase values are low with one exception (1922 Somogyi units) during exacerbation of pancreatitis. Characteristic zymogram of macroamylase on electrophoresis is also reported.