Ｏｂｊｅｃｔｉｖｅ　To investigate effects of dexmedetomidine(Dex) on alveolar fluid clearance (AFC) in rats with acute lung injury induced by lipopolysaccharide (LPS).　Methods　Forty-eight male Wistar rats were randomly divided into normal saline control (NS) group, LPS group, and Dex treatment (LPS+Dex) group. The rats in NS group were intravenously injected with 0.9% normal saline (5 ml/kg) followed by influsion of 0.9% normal saline (5 μg·kg-1·h-1). The rats in LPS group were intravenously injected with LPS (10 mg/kg) followed by influsion of 0.9% normal saline (5 μg·kg-1·h-1). The rats in LPS+Dex group were intravenously injected with LPS (10 mg/kg) followed by influsion of Dex (5 μg·kg-1·h-1). The rats were sacrificed 6 h after intravenous injection of LPS or NS, PaO2 was measured, AFC was determined by Evans blue-tagged albumin concentration changes. Histology of the lungs were assayed with H-E staining. The wet/dry weight ratio (W/D) of the lung was determined. The levels of TNF-α and IL-1β in the lung tissues were assessed by ELISA. The protein levels of potassium sodium adenosine triphosphate enzyme (Na-K-ATPase), alveolar epithelial sodium channel (ENaC) were detected by Western blot and immunohistochemistry.　Results　Compared with NS group, PaO2 was lower in LPS group, and this drop was reversed by Dex (in LPS+Dex group)(P<0.01). The W/D and the concentrations of TNF-α and IL-1β in the pulmonary tissues were increased in the LPS group, relative to the NS group, but the increases were compromised in the LPS+Dex group(P<0.01). AFC was reduced in LPS group, relative to NS group, but the reduction was compensat in LPS+Dex group(P<0.01). The expression of Na-K-ATPase and ENaC was lower in the LPS group than the NS group, but they were normalized in the LPS+Dex group(P<0.01).　Conclusions　Our findings suggest that dexmedetomidine may alleviate pulmonary edema by increasing AFC and the expression of Na-K-ATPase and ENaC in rats with acute lung injury induced by lipopolysaccharide.