Objective To investigate the role of dexmedetomidine (DEX) in lipopolysaccharide (LPS)-induced release of cell cytokines from monocyte macrophage RAW264.7 and nuclear transcription factor (NF)-κB signal pathway. Methods RAW264.7 cell lines were seeded in 6-well plates with a density of 1×106/mL (2 mL/hole) and randomly divided into control group (PBS), DEX group (10 ng/mL), LPS group (1 μg/mL) and LPS (1 μg/mL)+DEX (10 ng/mL) group. After incubation of 3, 6, 12 and 24 h, ELISA was employed to detect the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1βand high mobility group box (HMGB)-1 in the supernatants of 6 wells in each group. Then, 6 wells in each group were chosen at incubation of 12 h for determination of NF-κB signal pathway related proteins phosphorylated (p)-P65 and p-P50 expressions by Western blotting. Results As compared with those in the control group, the concentrations of TNF-α, IL-1β and HMGB-1 in the supernatant of LPS group were significantly increased (P<0.05), and the expressions of p-P65 and p-P50 were significantly increased in the LPS group (P<0.05). As compared with those in the LPS group, the levels of TNF-α, IL-1β and HMGB-1 were statistically decreased, and the expressions of P65 and P50 were significantly down-regulated in the DEX group (P<0.05). Conclusion DEX could inhibit the release of cells cytokines from RAW264.7 and decrease the levels of NF-κB signal pathway related protein expressions.