Abstract: Objective The purpose of this study was to observe the apoptosis of A2780 cells transfected with the recombinant plasmid of pcDNA-Bax and to observe the release of cytochrome C from the mitochondria. Methods The recombinant plasmid of pcDNA-Bax was constructed and transfected into A2784 cells. The Hoechst 33258 stain method was applied to evaluate the apoptosis of the transfected cells and MTT mothod was used to test the cell viability. Western blot analysis was performed to determine the overexpression of Bax and the release of cytochrome C from the mitochondria. Results The recombinant plasmid of pcDNA-Bax was successfully constructed by using endonuclease digestion and the sequence analysis. The apoptosis of A2780 cells was induced after transfected with pcDNA3.1-Bax as demonstrated with Hoechst staining. The cell viability were decreased in the pcDNA3.1-Bax transfected group by MTT assay. The release of cytochrome C from the mitochondria was observed when using Western blotting analysis. And the caspase-9 and the caspase-3 were activated. Conclusion Our data suggestted that Bax exhibited potent pro-apoptotic activity against the ovarian cancer cells. This study is a foundation for the further research in the pro-apoptotic activity of Bax.