PURPOSE: To provide the heat development method capable of obtaining an improved minimum density and an excellent maximum density and excellent gradation.

CONSTITUTION: The heat-developable photosensitive material containing a dye donor to be allowed to form or to release a diffusive dye at the time of heat development is heated after exposure or simultaneously with this to form or to release the diffusive dye and to diffuse the dye to an image receiving layer to transfer the image. This heat development is characterized to be carried out in the presence of at least one kind of compound represented by the formula: R-X, and at least one kind of compound represented by the formula: R'-SM, and in these formulae, R is optionally substituted alkyl, alkenyl, cyclo-alkyl, or cycloalkenyl; X is halogen; R' is an aromatic, aliphatic, or heterocyclic group; M is H, an alkali metal atom, or an ammonium group; and when R'-SM is R'-SH, its molecular weight is ≤300.