Objective To investigate the effect of aerosolized perfluorocarbon (PFC) (FC77) on gas exchange，histopathological changes of lung in acute lung injury and pulmonary expression of tumor necrosis factor-α (TNF-α) mRNA.Methods After acute lung injury (ALI) was induced by oleic acid (OA)，16 rabbits were assigned randomly into 2 groups,ie.aerosolized perfluorocarbon group (PFC group) and conventional mechanical ventilation group (CMV group).Gas exchange parameters were measured before and after ALI，at 1，2，3，4 h after treatment.Histological sections taken from 6 different parts of lung were stained by hematoxylin and eosion.The express of TNF-α mRNA in the 2 different parts of lung were detected by in situ hybridization (ISH).Results Compared with CMV group，the PaO2 and static lung compliance (CLst) were significantly increased (Plt;0.05)，the histopathological lesions of lung were attenuated，and the TNF-α mRNA expression was decreased significantly in PFC group (all Plt;0.05).There was more expression of TNF-α mRNA in backside than that in foreside of lung in two groups (Plt;0.05).Conclusion Aerosolized perfluorocarbon (PFC) can decrease expression of tumor necrosis factor-α mRNA in the lung，and improve the CLst and oxygenation during acute lung injury.