Abstract: Objective To study imbalance between EGF and TGFβ1 signal in fetal rat alveolar epithelial type 2 cell exposed to oxygen. Methods Primary fetal rat type 2 alveolar epithelial cells were randomized divided into 2 groups: air group and O2 group. Cell apoptosis were measured by FACS. Sprouty2、EGF receptor、phospho-EGF receptor（Tyr1148）、phospho-EGF receptor（Tyr845）and TGF-βⅡreceptor were was tested by western blot. Sprouty2 mRNA were measured by real-time PCR. Results Compared with air group, there was increased cell apoptosis in O2 group according to FACS. Sprouty2 mRNA and protein were increased in O2 group than air group. EGF receptor、phospho-EGF receptor（Tyr1148）、phospho-EGFreceptor（Tyr845）were decreased in O2 group compared with air group while TGF-βⅡreceptor expression was increased in O2 group compared with air group. Conclusion EGF which can decrease Sprouty2 expression is downregulated in fetal rat alveolar epithelial type 2 cells exposed to oxygen. TGFβ1 which can increase Sprouty2 expression is upregulated in fetal rat alveolar epithelial type 2 cell exposed to oxygen. Both of these 2 mechanisms cause further rising of Sprouty2. We think this is very important in BPD.