The evaluation of color fading of dark faded color patches (C, M or Y) prepared with color slide films was examined from the change of color difference ( ΔE *) calculated from L*a*b * system. As the fading condition, the patches were kept at 70±0.5°C and 75±1.0% RH for up to 4 weeks, and their color densities ( D_R , D_G or D_B ) and tristimulus values ( X , Y , Z ) were measured every 4 days. From the results obtained on the relation between the decrease of color density and the amounts of ΔE* for each patch at various fading time, there was the remarkable difference of the color fading situation between coupler-in-emulsion type and coupler-in-developer type color slide films. At the former type films, color density of yellow patch increased rapidly in initial fading time for generation of yellow stain, but the density of the patch with the latter decreased gradually according to increase the fading time. However, it was found that there was not necessarily to exist the correlation between the amounts of color difference and decrease of density. The ratio of the amount of three components ( ΔH *, ΔC * and ΔL *) in ΔE * which have an effect on chromaticity, was also changed according to increase the fading time. It became clear that those components respect the character of fading such as the direction and amount of changed color.