Abstract： Objective To observe the effects of mesenteric lymph duct ligation on platelet function, thrombus formation in vitro and coagulation function in rats with acute loss of blood, and investigate the role of intestinal lymphatic pathway on coagulability change during acute loss of blood. Methods Twenty male Wistar rats were randomly divided into loss of blood group (n=10) and ligation group (n=10). The acute loss of blood model was reproduced by withdrawing blood (one fourth of body whole blood volume) with an automatic withdrawal-infusion machine through right common carotid artery. In ligation group, the mesenteric lymph duct was ligated after loss of blood, and in loss of blood group only a thread was passed under the mesenteric lymph duct. The rats′ survival rate at 24 hours was recorded. After 24 hours, surviving rats were anesthetized again, and 6 ml of blood was withdrew from left common carotid artery rapidly. The platelet adhesive rate, platelet aggregation rate, thrombus formation in vitro, coagulation function were determined before and after experiment, and the cerebral blood flow was measured. Results There were 6 rats alive in loss of blood group (60%), and 9 rats alive in ligation group (90%). The platelet adhesive rate, platelet aggregation rate, fibrinogen (Fib) content were increased in both groups, and cerebral blood flow was lower compared with before experiment significantly. The activated partial thromboplastin time (APTT) in loss of blood group, and thrombin time (TT) in both groups were prolonged. And the length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus and thrombus formation rate in loss of blood group were significantly increased compared with before experiment (P<0.05 or P<0.01). But in ligation group, the platelet adhesive rate [(15.02±1.24)%], platelet aggregation rate (at 1 minute, 3 minutes and max aggregation rate), length of wet thrombus, wet weight of thrombus, length of dry thrombus, dry weight of thrombus, thrombus formation rate [(46.2±6.9)%], APTT [(21.04±5.53)s] and Fib content [(433.67±13.97) g/L] were lower, cerebral blood flow [(485.1±41.4) ml·kg~(-1)·min-1] was higher compared with loss of blood group, respectively [(18.54±1.18)%, (69.8±6.9)%, (26.35±6.26)s, (510.96±35.59) g/L, (417.8±42.2) ml·kg~(-1)·min~(-1), P<0.05 or P<0.01]. Conclusion The results indicate that acute loss of blood leads to coagulation and increased thrombosis, and mesenteric lymph duct ligation can improve hypercoagubility of blood.