[Abstract] Objective: To assess the intervention effects of different doses vaporized perfluorocarbon(PFC) inhalation pretreatment in rabbits with oleic acid(OA) induced acute lung injury(ALI), and to obtain the minimum effective pretreatment dose. Methods: Twenty-four New Zealand rabbits were randomly divided into 4 groups(n=6 each): normal control group(group C), PFC pretreatment by 1 ml•kg-1•h-1 group(PFC-1), PFC pretreatment by 2 ml•kg-1•h-1 group(PFC-2) and PFC pretreatment by 3 ml•kg-1•h-1 group(PFC-3). All rabbits were anesthetized and mechanically ventilated by tracheal intubation. Group C was induced ALI by OA after mechanically ventilated for 60 min. Three PFC pretreatment groups were vaporized inhalation PFC separately by 1 ml•kg-1•h-1, 2 ml•kg-1•h-1 and 3 ml•kg-1•h-1 for 60 min before ALI induced. After then four groups were mechanically ventilated for 120 min. Oxygenation indexes(PaO2/FiO2)were measured at baseline, when the PFC pretreatment finished (Group C were measured when mechanically ventilated for 60 min.), when ALI was just established, and 120 min after ALI. After above operations，samples of the blood serum were obtained by centrifugation of the venous blood，and lung lavage fluid was obtained by lavaging the left lung. The concentrations of TNF-α and IL-1β in blood serum and lung lavage fluid were detected by ELISA. Results: Compare to group C[(477±5),(472±5),(103±5),(69±4)], PaO2/FiO2 in three PFC[PFC-1(474±11, 478±4, 122±12, 83±5), PFC-2 (472±10, 478±4, 140±11, 88±3), PFC-3(479±9, 480±6, 146±15, 86±2)] were significantly increased (P<0.05). Among the PFC pretreatment groups, PaO2/FiO2 raised significantly both in PFC-2 and PFC-3 when compared with PFC-1(P<0.05). Compare to group C(229±5pg/ml), the concentrations of TNF-α in three PFC [PFC-1(220±5 pg/ml), PFC-2(209±3 pg/ml), PFC-3(212±3 pg/ml)] were significantly reduced(P<0.05) in blood serum, and it decreased significantly in PFC-2 and PFC-3 when compared with PFC-1(P<0.05). In lung lavage fluid, The concentrations of TNF-α in PFC-2 (323±9 pg/ml) and PFC-3(344±12 pg/ml) were both significantly lower than that in group C(365±14 pg/ml) and PFC-1(367±13 pg/ml)(P<0.05), and it is significantly decreased in PFC-2 when compared with PFC-3(P<0.05). The concentrations of IL-1β in blood serum [group C (102±3 pg/ml), PFC-1(100±3 pg/ml), PFC-2(77±1 pg/ml), PFC-3(84±2 pg/ml)] and lung lavage fluid[group C(116±2 pg/ml), PFC-1(116±3 pg/ml), PFC-2(93±2 pg/ml), PFC-3(96±4 pg/ml)] were both significantly lower than that in group C and PFC-1(P<0.05), there is significantly reduced in PFC-2 when compared with PFC-3 in blood serum(P<0.05). Conclusion: After vaporized PFC inhalation pretreatment by 2 ml•kg-1•h-1 and 3 ml•kg-1•h-1 can improve oxygenation and decrease the release of TNF-α and IL-1β in rabbits with OA-induced ALI, but there is no dose-depedent effect difference between the two groups, so the minimum effective pretreatment dose is 2ml/kg/h in three PFC pretreatment groups.