Disclosed is a manufacturing process of a sintered iron-copper base porous alloy and of an oil-impregnated sintered bearings, having the steps of: preparing a mixed powder comprising an iron powder, and at least one of a copper powder and a copper alloy powder; forming the mixed powder into a green compact; and sintering the green compact to obtain a sintered iron-copper base porous alloy. The iron powder contains a porous iron powder which has a particle size of 177 microns or less and a specific surface area of 110 to 500 m.sup.2/kg according to a gas adsorption method. The sintered compact has high intercommunicating porosity and low permeability, and it is sized to prepare the sintered bearing into which a lubricating oil is impregnated.
