PURPOSE: To obtain a positive image enabling clear discrimination between the image and non-image parts and having increased transfer density by bringing a thermally diffusible and transferable dye and the oxidized product of a reducing agent into a coupling reaction by heat development, and diffusing and transferring a thermally diffusible and transferable dye which does not take part in the reaction to an image receiving layer.

CONSTITUTION: When a thermally diffusible and transferable dye is a dye which forms a thermally nondiffusible and transferable substance by a coupling reaction with the oxidized product of a reducing agent by heat development, the dye is a hydrophobic dye, the reducing agent is a reducing agent having a hydrophilic group, and the hydrophobic dye forms a hydrophilic substance by a coupling reaction with the oxidized product of the reducing agent having a hydrophilic group by heat development. A hydrophobic polymer layer is used as an image receiving layer, and a hydrophilic binder is preferably used as a binder. A positive image is obtd. by heat development using a thermally diffusible and transferable dye losing its hydrophobic property by a coupling reaction with the oxidized product of a reducing agent having a hydrophilic group.