RAW264.7 cells may be considered as a cell model for study on interactions between E. tarda and macrophages. MOIs of 10:1 and 100:1 are recommended for using E. tarda-invaded RAW264.7 cells. E. tarda could induce the apoptosis in RAW264.7 cells through the involvement of caspase-3. Once inside macrophage, numberous E. tarda could be destroyed within the phagolysosomes. E. tarda who successfully subvert phagocyte defenses could replicate within the vacuolar-like compartment in macrophages.