Abstract: In order to study the effect of wetting alteration agents to porous flow process,the microscopic porous flow mechanics was studied,contact angle of solid surface was measured by contact angle method and Washburn method,oil-water interfacial tension was measured by interfacial tensiometer,and the effect of the wetting alteration agents to the wettability of oil-wet surface was also studied.Finally,the porous flow mechanics of wetting alteration agents was studied by microscopic model.The experiments shows that the wetting alteration agents can change surface wettability,also it can reduce oil-water interfacial tension to 10-1mN/m;and during the porous flow process,peeled off oil film,formed oil bridge and altered wettability.This study displays that both oil-water interfacial tension and wettability of rock surface influence the characteristics of porous flow,and it provide a good base for more study to improve porous flow of oil and water.