To provide a heat developable sensitive material excellent in development progressing property in heat development and capable of forming an image free of dot unevenness and having a high contrast, a high maximum density and few black spots, and to provide an image forming method using the same.

In the heat developable sensitive material having on a support one or more image forming layers containing at least a non-photosensitive organic silver salt, a reducing agent for the silver salt, a photosensitive silver halide, a contrast enhancer and a binder, and one or more non-photosensitive layers for protecting the image forming layers, the contrast enhancer is a compound selected from the formulae (1)-(3) and a surface elastic modulus of a side with the image forming layers at a heat developing temperature is set to 0.01-0.10 GPa.