Foam microscopic seepage experiments show that foam present two seepage states: Flowing foam and trapped foam.Foam plugging experiment show that foam plugging ability has accumulating effect.Plugging pressure gradient near core inlet is less than that of downstream of the core when foam flooding reaches steady state.A multi-component mathematical model characterizing foam flooding is established based on bubble population balance theory and foam properties.The model is solved numerically with fully implicit method.Validity of the model is verified with foam plugging experiment.Meanwhile,foam microscopic seepage characteristic parameters such as foam texture,pressure and aqueous phase saturation in foam flooding are studied.