Accessibility，stability and regeneration of the foam in various permeabilities and pore-throats were studied using etched glass micro-model and sand pack core model. Microscopic profile control and displacement mechanism under different permeabilities were studied. The foam has the lowest injection pressure. Foam stability gets better in high permeability layers；regeneration of foam is closely related to pore-throat size，pore-throat ratio and pore coordination number；oil washing and plugging by profile control of the foam in various pore-throats may enhance oil recovery with different contribution ratios. In high permeability and large pore-throat layers，the enhancement of recovery relies on plugging by profile control；while in low permeability and small pore-throat layers，oil washing is the main function. In the future，application of the foam to reservoir heterogeneity modification will be the research direction of oilfield chemistry.