A method of forming an image comprising the steps of: (a) exposing a photothermographic material comprising a support having thereon an image forming layer comprising organic silver salt grains, silver halide grains, a reducing agent, a development accelerator and a binder, the image forming layer being formed by application of a coating composition comprising more than 30% water as a solvent of the coating composition, and (b) conducting thermal development of the exposed photothermographic material employing a thermal developing device at a distance of 0 to 50 cm between an exposing section and a developing section to obtain a maximum density of 3.8 to 5.0 of the photothermographic material after the thermal development.