Abstract: OBJECTIVE To investigate the effects of early administration of arginine vasopressin(AVP) on blood perfusion and organ function of uncontrolled hemorrhagic shock rats. METHODS Ninety-six SD rats were divided into AVP group (5×10^-4 U·mL^-1 AVP with hypotensive resuscitation) and control group(hypotensive resuscitation). Uncontrolled hemorrhagic shock model was adopted, the effects of early administration (to mimic the pre-hospital treatment period) of AVP to maintain the blood pressure (50 mmHg, 3 h) on cardiac function, blood perfusion, vital organ and mitochondrial function were observed. RESULTS Early application of AVP significantly improved the cardiac function, increased cardiac output and oxygen delivery and oxygen utilization, improved hepatic blood flow, protected the hepatic function and its mitochondrial function in shock rats, as compared with hypotensive resuscitation alone. But the renal blood flow in AVP group was lower than that in control group, and the renal function and its mitochondrial function were not different between the two groups. CONCLUSION Early AVP therapys effectively improves cardiac function, increases tissue blood flow and protects hepatic mitochondrial function, final plays the anti-shock effects. But the role of AVP on renal function following shock needs further elucidation.