To provide a color diffusion transfer photosensitive material in which a high image density and excellent color reproducibility can be obtd. even at a low temp., an image can be obtd. in a short time, and the completed image shows little changes in density.

This photosensitive material has, on a supporting body, at least two photosensitive silver halide emulsion layers combined with a non-diffusive dye image forming compd. which forms or releases diffusive dyes (or precursors) on silver development or combined with a dye image forming compd. whose own diffusion property changes. In this material, a color mixing preventing layer is interposed between the emulsion layers. The color mixing preventing layer is formed by applying a dispersion material prepared by dispersing particles which are the integrated body of a non- diffusive reducing agent and a single polymer or copolymer, where the dispersion medium is a hydrophilic org. colloid. The polymer or copolymer has a repeating unit having a -C(=O)-O- bond in the main chain or side chains and is insoluble in water but soluble in a low-boiling point org. solvent. The average size of the particles is 0.1 to 0.3 μm. The content of a low boiling point org. solvent is 0.2 to 4 wt.%. The weight ratio of the polymer to the hydrophilic org. colloid is 0.2 to 1.5.