Abstract Purpose: To investigate the impacts of albumin synergized with hydroxyethyl starch (HES) on early microvascular albumin leakage after major abdominal surgery in rabbits. Methods: Forty male Japanese rabbits were randomly divided into four groups: the control group, the saline group, the albumin group, and the Syn group (hydroxyethyl starch+albumin). The latter three groups were performed gastrectomy plus resection of pancreatic body and tail and splenectomy. The serum albumin concentration was detected before and 48h after surgery, and the conditions of mesenteric microvascular leakage in these 4 groups were observed under microscope 48 h after surgery to calculate the leakage rate. Results: Compared with the saline group, the albumin group and the Syn group exhibited significantly increased serum albumin concentrations 48h after surgery (P<0.05). The albumin leakage rate was the most obvious in the albumin group, followed by the saline group, while that in the Syn group was the minimal, and there existed significant differences among these groups (P<0.05) . Conclusion: Simple administration of albumin in the early stage after major abdominal surgery could increase the albumin leakage, while the synergization of albumin and hydroxyethyl starch could reduce the albumin leakage.