To obtain a diffusion transfer image with excellent discrimination of the image, a high max. density and a fast developing rate by image-exposing a color diffusion transfer photosensitive element consisting of direct positive silver halide emulsion layers, then developing the element by using an alkali treating compsn. containing a specified developing agent.

After a color diffusion transfer photosensitive element consisting of inner latent image type direct positive silver halide emulsion layers is exposed according to image, the element is developed by using an alkali treating compsn. containing two kinds of developing agents each having the average oxidation- reduction potential from -150 to -140 mV (based on a saturated calomel electrode). The inner latent image type direct positive silver halide emulsion contains silver halide particles having a composite structure prepared in such a manner that a silver halide phase formed on the surface of the silver halide particle has higher iodine content in the silver halide than the iodine content in the silver halide of the inner phase of the particle, and the average iodine content to the whole particles is <1.0 mol.%.