Objective To investigate the effect and mechanism of Clara cell secretory protein (CC16 ) on lung injury of traumatic shock rats.Methods Thirty SD male rats were randomly assigned to three groups:sham-operation group,control group and CC16-treatment group.The rat model of traumatic shock was used in this study.Rats of sham-operation group were operated,but not treated by depletion and recovery.Rats of control group inhaled the physiological saline before fluid resuscitation.Rats of CC16-treatment group inhaled 0.1 μg/mL of recombinant human Clara cell secretory protein (rh-CCSP)before fluid resuscitation.Arterial blood gas analysis and wet/dry weight were detected in each group.The contents of malondialdehyde (MDA),myeloperoxidase (MPO)of lung tissues and lung tissue pathology changes were also studied. Results Compared with control group,pH and PaO2 value in CC16-treatment group increased significantly.Meanwhile,BE value and lung wet/dry weight ratio also decreased significantly (P<0.05).Compared with control group,contents of MDA and MPO in CC16-treatment group decreased significantly (P<0.05).Lung tissue pathology improved in the CC16 group compared with that of control group (P <0.05 ).Conclusion Inhaled Rh-CCSP may have potential protective effect on lung injury tissues of traumatic shock rats model through its antioxidative effect.