Abstract: Objective To research the mechanism of High Volume Hemofiltration (HVHF) on acute lung injury (ALI) induced by LPS in dogs . Methods After injected LPS (650μg/kg) via central vein within 30min, Sixteen healthy hybrid male dogs were divided into control group and treatment group randomly (n=8) .PH、PaO2 、PaCO2 in artery blood were recorded . Contents of TNF-α、IL-6 and IL-10 in plasm were measured by radioimmunity . The activity of NF-кB in lung homogenate was measured by flow cytometer . The content of surfactant protein B (SP-B) in lung homogenate was measured by protein Western-blotting.Changes of lung histopathology was observed via electron microscope. Results After injection of LPS , PaO2 and PaO2/FiO2 began to decrease. PaO2 and PaO2/FiO2 in treatment group kept higher than that in control group (P<0.01) . In treatment group, the content of TNF-α、IL-6、IL-10 in plasm obviously decreased after HVHF and the activation of NF-κB were also decreased. There was very significant difference at the same time between two groups (P<0.01). The content of SP-B in lung homogenate in treatment group was significantly higher than that in control group (P<0.01). Edema of alveoli and lung mesenchymal,hemorrhage,infiltration of inflammatory cells and the injury of PC-II in treatment group were obviously lightened after HVHF . Conclusion HVHF can relieve ALI induced by LPS in dogs, which is contributed to the continuously elimination of inflammatory medators , the inhibition of activation of NF-κB then the down regulation of high expression of cytokines , the attenuation of mesenchymal and alveolar inflammatory edema , and the increase of content of SP-B.