Ursodeoxycholic acid is a chemical preparation of natural bile acid isolated from bear bile juice. It is a stereoisomer of chenodeoxycholic acid. Its litholytic effect and curative effect are similar to chenodeoxycholic acid, but the course of treatment is short and the dosage is small. It is a kind of hydrophilic cholic acid and a kind of cholesterol stone dissolving agent. It can reduce the secretion of cholesterol by liver, reduce the saturation of cholesterol in bile, promote the secretion of bile acid, increase the solubility of cholesterol in bile, dissolve cholesterol stones or prevent the formation of stones. It can increase the amount of bile secretion, relax the sphincter of bile duct mouth, produce cholagogic effect, which is conducive to the discharge of stones. This product can not dissolve other types of gallstones. Ursodeoxycholic acid is suitable for the treatment of cholesterol gallstones, hyperlipidemia, bile secretion disorders, primary biliary cirrhosis, chronic hepatitis, bile reflux gastritis and prevention of acute rejection and reaction of liver transplantation. The stone dissolving effect of this product is slightly weaker than that of chenodeoxycholic acid.