Abstract: Objective To investigate the influence of calcium intake on mRNA expressions of key enzyme of hepatic cholesterol metabolism,HMDC oAreductase and CYP7A in hyperchole sterolemic rats.Methods Four week old male Wistar rats,following 2 weeks of inducing hypercho lesterolemia model successfully,were fed with purified expermiental diets containing 0.5%(Group B),1.0%(Group C)and 2.0%(Group D)calcium with high fat concentration for 6 weeks.At the end of the experiment,the concentration of total cholesterol(TC),the mRNA expressions of HMDCo Areductase and CYP7A of the rats were examined.Results Compared with the initial of the expermient,TC was(2.32±0.75)mmol/L dropped by 6.07%(P<0.05)in group B.Greater inhibition in elevation of serum cholesterol concentration was observed in group C than in group A.Calcium intake tended to decrease the mRNA ex pression o f hepatic HMDC oA reductase and increase the mRNA expression of CYP7A in the rats.Conclusion A dequatecalc iumintake decreasses the level of serum total cholesterol in hypercho lestero lemic rats.Calcium in take also influences the mRNA expression of HMDCoA reductase and CYP7A.