Objective To investigate the effect of volume therapy with 6％ hydroxyethyl starch (HES) 130/0.4 on mesenteric microcirculation in a rabbit model of hypovolemia.Methods Sixty-four adult male rabbits,weighing 2.0-2.3 kg,were randomly divided into 4 groups( n =16 each):control group (group C),hypovolemia group (group HM),Ringer's solution group (group RS) and 6％ HES 130/0.4 group (group HES).The animals were anesthetized with sodiun pentobarbital 3.0-3.5 mg/kg.Femoral artery,femoral vein and right internal jugular vein were cannulated for MAP monitoring,blood withdrawing and fluid adminstration.Hypovolemia was induced by withdrawing blood from femoral vein of 30％ blood volume in 30 min in groups HM,RS and HES.In group C,no blood was withdrawed.In group RS,Ringer's solution 3 times of the volume of blood withdrawn was infused,while 6％ HES 130/0.4 equal volume of blood withdrawn was infused via right internal jugular vein immediately at the end of blood withdrawing.MAP and HR were recorded and femoral artery and femoral vein blood samples were taken before blood withdrawing (T0),immediately at the end of blood withdrawing(T1 ),immediately at the end of volume therapy(T2 ) and 30 min after volume therapy(T3 ).DO2,VO2 and ERO2 were calculated.Diameter and blood flow speed of microvessel were determined.Results Compared with group C,HR was significantly increased,MAP decreased,diameter and blood flow speed of microvessel were decreased at T1～3,DO2 was increased　at T1 in group HM.Compared with group HM,MAP was significantly increased at T2,HR decreased at T2,3,DO2and VO2 were increased at T1～3,diameter of arteriole was increased at T2 whlie decreased at T3,diameter of veinule　and blood flow speed of microvessel were increased at T2,3 in group RS,MAP was significantly increased at T2,HR　was decreased whlie DO2 and VO2 were decreased,VO2,ERO2,diameter and blood flow speed of microvessel were　increased at T2,3 in group HES.Compared with group RS,DO2,VO2 and ERO2 were significantly decreased at T3　in group HES.Conclusion Volume therapy with 6％ HES 130/0.4 can improve mesenteric microcirculation,organ perfusion and oxygen metabolic in a rabbit model of hypovolemia.