It was found that dexmedetomidine at the doses of 10 and 20 μg/kg decreased CLP-induced pulmonary inflammation and mortality, reduced production of IL-6 and TNF-α in plasma and BALF of septic rats, and suppressed TLR4/MyD88 expression and NF-κB activation in lung of endotoxemia rats induced by CLP. This evidence concerns the gene NFKB1 and serum lipopolysaccharide activity.