Objective: To observe the influence of HES on coagulation-fibrinolysis system during perioperative stage.Methods: 34 I~II grade ASA patients were randomly selected and divided into two groups.Group A(n=18) was transfused 1000ml HES

group B(n=16) transfused with 1000ml of equilibrium liquid 1000ml

both at the rate of 25ml/Kg /h

then both transfused with equilibrium liquid at the rate of 500ml/hr.coagulation-fibrinolysis parameters of coagulation starting time(CST)

maximum coagulation time(MCT)

the whole time of fibrinolysis reaction(WFT)

the balance time(BLT)

maximum extent of coagulation(MCE) were measured by dynamicgraphy instrument(CFD-III).Blood plasma thrombin

F.IIa and Plasminogen

Plg were measured at the preoperation

the end of transfuse of 1000ml of liquor instantly and 2 hr later

respectively.Results: F.IIa and Plg in two groups decreased

but no significant difference was found a many different time paints in the serve group(P>0.05) The companrison at the same time paint showed no significant difference between two groups(P>0.05).Conclusion : Transfuse of 1000ml HES at perioperative stage could proliferate blood volume

and have mild influence on coagulation-fibrinolysis system without anaphylactoid reaction.It could be safely used at perioperative stage.