Abstract: An image forming method comprising the steps of:(a) superposing a heat development photosensitive material on a sheet after or simultaneously with imagewise exposing the heat development photosensitive material, wherein the photosensitive material comprises a support having thereon at least a photosensitive silver halide, a hydrophilic binder and a slightly water-soluble basic metal compound, and the sheet comprises a support having thereon at least a compound which forms a complex with the metal ion constituting the basic metal compound, a solvent for a silver halide and a physical development nucleus; and(b) heat developing the laminate in the presence of a reducing agent and water to form an image on either or both of the photosensitive material and the sheet,wherein the reducing agent comprises a 1-phenyl-3-pyrazolidone compound and a dihydroxybenzene compound having an inorganic value of not less than 215 and an organic value of from 120 to 400.