Objective To observe the efficacy of hydrogel dressings in preventing and treating vein injury of rabbits so as to provide a experimental evidence for cl inical appl ication. Methods Twenty-four healthy large-eared Japanese rabbits (48 ears) were choosen, weighing (2.15 ± 0.15) kg, and divided into 3 groups randomly. The vein injury models were made byintravenously infusing 20% mannite (2.5 mL/kg). The sites of puncture were treated with hydrogel dressings (group A, n=8) and 25%MgSO4 (group B, n=8) 5 minutes after infusion. The sites of puncture were not treated as a blank control (group C, n=8). The tissue specimens were collected from the auricular veins at 24 hours after mannite infusion for histological observation by HE staining. The injury of the vessel wall, hemorrhage around the vessels, infiltration of inflammatory cells, and disturbance of circulation were observed to evaluate the injury degree of vein. Results There existed redness and congestion in the injured veins of each group. HE staining showed that in both groups A and B, the vessel wall was sl ightly injured and hemorrhage around the vessel was mild. There existed infiltration of inflammatory cells in the vessel wall and surrounding tissues. There also existed congestion and thrombus in the vessel lumen in these two groups. While in group C, the injury of vessel wall was severe, and schistic bleeding in the surrounding tissue of the vessel was existed. The severe congestion and thrombus in the vessel lumen was observed. There was no significant difference among three groups in the extent of vein wall injury and hemorrhage around the vessel (P gt; 0.05). The degree of infiltration of inflammatory cells and circulatory disturbance in both groups A and B were significantly less than that of group C (P lt; 0.05); but there was no significant difference between groups A and B (P gt; 0.05). Conclusion Hydrogel dressing is helpful to prevent vein injury of rabbits induced by mannite.