Abstract: Objective To study the protective effect of dexmedetomidine against perioperative inflammation and on pulmonary function in patients undergoing radical resection of lung cancer. Methods From May, 2014 to May, 2016, 124 patients with lung cancer receiving radical surgeries were randomized into experimental group (n=62) and control group (n=62). The patients in the control group received a single anesthetic agent for anesthesia, and additional dexmedetomidine was given in the experimental group. The levels of serum interleukin-1β (IL-1β), IL-10, and tumor necrosis factor-alpha (TNF-α) were measured before the operation (T0), at 30 min (T1) and 60 min (T2) during one lung ventilation (OLV) and at the end of operation (T3). Enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of malondialdehyde (MDA), myeloperoxidase (MPO) and xanthine oxidase (XOD), and the arterial oxygen partial pressure (PaO2), oxygenation index (OI), airway plateau pressure (APP) and airway resistance (AR) were also recorded. Results At the time points of T1 and T2, IL-1β, IL-10, MDA, MPO, TNF-α, and XOD levels were significantly increased in both of the groups, but the levels of IL-1, IL-10, TNF-α and MDA were significantly lower and MPO and XOD levels significantly higher in the experimental group than in the control group (P< 0.05). In both groups, PaO2 and OI decreased and APP and AR increased significantly at T1 and T2, but APP and AR were significantly lower and PaO2 and OI significantly higher in the experimental group than in the control group (P<0.05). Conclusion Anesthesia with dexmedetomidine in lung cancer patients undergoing radical surgery can effectively reduce the inflammatory response of the lungs and protect the lung function of the patients.