Objective To observe the effect of Sagitta sagittifolia polysaccharide on glucose and lipid metabolism in mice with nonalcoholic fatty liver disease（ NAFLD） induced by high fat diet and discuss its possible action mechanism. Methods SPF grade ICR mice（ n = 26） were randomly divided into three groups: control group,model group,and polysaccharide group（ n = 8 in control and polysaccharide group,n = 10 in model group）. The mice in the model and polysaccharide groups were fed with high fat diet（ MCD） to establish NAFLD model,meanwhile,the polysaccharide group was given Sagitta sagittifolia polysaccharide. Serumtriglyceride（ TG）,total cholesterol（ TC） fasting blood-glucose（ FBG） and free fatty acids（ FFA） were tested by full automatic biochemical analyzer. The histomorphology of liver was observed by HE staining and oil red 0 staining,and the expressions of TNF-α,IL-6,PGC-1α mRNA in liver tissue were detected by PCR. Results Compared with the control group,the serum levels of TG,TC,FBG and FFA in the model group were higher than those in the control group（ P < 0. 01）. Liver tissue showed moderate steatosis accompanied by inflammation and necrosis,and the expression of TNF-α,IL-6 mRNA was increased in liver tissue（ P < 0. 05）. The expression of PGC-1α mRNA was decreased（ P < 0. 01）. Compared with the model group,the level of serum TG,TC,FBG and FFA in polysaccharide group decreased（ P < 0. 05）. The expression of TNF-α and IL-6 mRNA was decreased in liver tissue（ P < 0. 05 or P < 0. 01）. The expression of PGC-1α mRNA was increased（ P < 0. 01）. Conclusion Sagitta sagittifolia polysaccharide can significantly regulate the metabolism of glucose and lipid in NAFLD mice,its mechanism may be related with the up-regulation of the expression of PGC-1α mRNA,and decrease of the expression of TNF-α and IL-6 mRNA.