Aim To study effects of acute normovolemic hemodilution on hemodynamics,hemorheology,during Operation on coronary heart disease patierts.Methods Twenty-eight Coronary heart disease patients of sexes(18 male,10 female)aged 44-61 yr weighing 54-79 kg undergoing elective operations were randomly divided into 2 groups with 14 patients in each group:Acute normovolemic hemodilution(ANH)group and control group.Right internal jugular vein was cannulated for CVP monitoring and blood sampling,Radial artery was cannulated for blood pressure monitoring and blood gas analysis,Femoral vein was cannulatel for blood sampling and fluid infusion.Blood(8-12 ml/kg)was removed from radial artery in ANH group and normovolemic was maintained by simultaneous infusion of 6% HEAS.ECG,BP,CVP were continuously monitored throughout the operation.Arterial and central venous blood samples were taken for blood gas analysis before and after ANH.Results There were no significant changes in HR,MAP and CVP after ANH.And there were no significant difference in parameters of blood gas analysis between two groups,But the control group needing blood infusion from another was much more than ANH group.Conclusion ANH can be safely used for coronary heart disease during operations,efficiently prevent losing of blood and may have heart protection function.