Research shows that the formation of cholesterol calculus is associated with a variety of factors, in the bile, cholesterol and phospholipids 
formation except the part "bubble", also dissolve in bile acid and phosphatidyl choline and form micelles, keeping higher concentration of 
the cholesterol in the bile, and dissolved state.As a result, the cholesterol in the bile, bile acid and phosphatidyl choline needs to keep a certain proportion.When the bile acid to reduce or increase cholesterol and cholesterol in supersaturated state (also called supersaturated bile, bile stone), can precipitate out crystallization, the formation of cholesterol calculus.
       Chenodeoxycholic acid (CDCA) is the primary bile acid composition in normal bile, as cholesterol gallstones of the solute. Chenodeoxycholic acid increases from bile, can change the proportion of bile salt and cholesterol in bile, and liver cells of cholesterol synthesis and secretion is reduced, thus reduce cholesterol levels in bile, at the same time also can reduce the intestinal absorption of cholesterol, and increase the bile acid, improve the solubility of cholesterol in bile, can make cholesterol calculus slowly dissolve, and the formation of new stone is restrained.The vast majority of patients after taking chenodeoxycholic acid of saturation to reduce cholesterol in bile, and restore the micelles.Generally when chenodeoxycholic acid accounted for 70% of bile salts in bile and cholesterol in the unsaturated state.Large doses of chenodeoxycholic acid (every 10 ~ 15mg/kg) can inhibit the synthesis of cholesterol, and increase the secretion of bile cholelith disease patients, but the amount of secretion of bile salt and lecithin remain unchanged.In addition,  chenodeoxycholic acid still reduce hyperlipidemia patients serum three acyl glycerin.