Abstract： Objective To explore the expressions of apoptosis gene Bcl-2 (B-cell leukemia-2) and Bad (bcl-xl/bcl-2-associated death promoter) in lung tissue of mice with acute lung injury (ALI). Method Twenty-four BALB/C female mice were randomly divided into control saline group (n = 6) and ALI group (n = 18). The ALI Group was further divided into 3 subgroups with 6 mice in each subgroup: ALI (4 h) ,ALI (6h) ,and ALI (8h) subgroups. Rats in the normal control group received injection of saline. The ALI models were produced by in-jection of oleic acid (0.9 mL/kg) via vena caudalis, and the criteria were met with the characteristically pathologi-cal changes in the lung tissue. Pathological changes of the lung tissue were examined and scored under light mi-croscopy 4 h,6 h and 8 hours after injury. The expressions of gene Bcl-2 and gene Bad were detected in lung tissue at above set intervals by using RT-PCR. Data of these assays were analyzed by using one-way ANOVA with SPSS version 13.0 software. Statistical significance was established at a P value of less than 0.05. Results The rela-tive magnitude of Bel-2 expression in ALI (4 h), ALI (6 h) and ALI (8 h) subgroups were significantly higher (58.00±5.31), (42.00±4.30), (32.51±10.40) as compared with the control group (24.30±1.00) (F =68.581, P < 0.05). The relative magnitude of Bad expressions in ALI (4 h), ALI(6 h) and ALI (8 h) sub-groups were signiticantly higher (29.32±1.19), (58.64±4.45), (95.12±4.34)as compared with control group (4.01±0.34) (F = 386.902,P < 0.05). The pathological scores ofhmg injury in ALI(4h), ALI (6 h) and ALI (8 h) subgroups were significantly higher (1.82±0.14), (2.52±0.25), (3.45±0.29) as compared with control group (0.27±0.03) (F = 260. 512, P <0.05). Comparisons between groups showed statistical signifi-cances (P < 0.05). Conclusions The aggravation of lung injury induced by oleic acid in mice related to the down-regulation of apoptosis gene Bcl-2 expression and up-regulating apoptosis gene Bad expression in lung tissue.