Macrophage is an important component of innate immunity, which plays a great role in anti-infection im- munity. The accurate evaluation of non-opsonic phagocytosis of macrophages is often used as an important indicator of the non-specific immune responses when bacterial infection occurs. In the present study, the non-opsonic phagocytosis of macrophages in resident or inflammatory infiltrating condition was quantificationally detected by using flow cyto- metry method combined with bacterial counts. This method will contribute to the quantitative evaluation for the ability of macrophage phagocytosis and the accurate response to macrophage immunity in a variety of physiological and pa- thological conditions.