Ｏｂｊｅｃｔｉｖｅ　To explore the effect of dexmedetomidine(Dex) on the release of cell cytokines from monocyte macrophage RAW264.7 cells induced by lipopolysaccharide(LPS) and the expression of heme oxygenase(HO)-1.　Methods　RAW264.7 cells were cultured in six-well culture dishes with a density of 1×106/ml(2 ml/hole) and were randomly divided into 5 groups (n=6) by the number table method: normal control group(C group), Dex 10 μg/L(Dex group), LPS 1 mg/L(LPS group), LPS 1 mg/L+Dex 10 μg/L(LPS+Dex group), and ZnPPⅨ(inhibitor of HO-1), 10 μmol/L+ LPS 1 mg/L+Dex, 10 μg/L(ZnPPⅨ+LPS+Dex group). After incubation of 3, 6, 12, 24 h, ELISA was used to determine the concentrations of TNF-α, IL-6 and high mobility group box-1 protein(HMGB-1) in the supernatants of six wells in each group. Then, six wells in each group were chosen at incubation of 6 h and 12 h for determination of HO-1 expression by Western blot.　Results　Comparing with C group, the concentrations of TNF-α, IL-6 and HMGB-1 in the supernatants at 3, 6, 12, 24 h in the LPS group were significantly increased(P<0.05), and the expression of HO-1 at 6 h and 12 h time point was up-regulated in LPS group. Compared with LPS group, the concentrations of TNF-α, IL-6 and HMGB-1 in LPS+Dex group were attenuated(P<0.05). Meanwhile, the expression of HO-1 at 6 h and 12 h time point was up-regulated in LPS+Dex group. Compared with LPS+Dex group, the concentrations of TNF-α, IL-6 and HMGB-1 in ZnPPⅨ+LPS+Dex group were increased(P<0.05). However, the expression of HO-1 was reduced in ZnPPⅨ+LPS+Dex group(P<0.05).　Conclusions　Dex could inhibit the release of cell cytokines from RAW264.7 via up-regulating the levels of HO-1 expression.