The purpose of this paper is to obtain information on the temperature dependence of the information capacity of B/W film developed by ordinary fine grain developers. The results of the experiments show that the light spread function of photographic layer is much improved as the temperature of development increases. The reason is considered that, at the higher temperatures, diffusion is rate controlling, the developed silver appeares in the upper portion of the emulsion layer, thus light spread function which increases along the depth of emulsion layer would be improve as the diffusion is rate controlling state. While, RMS granularity of the emulsion layer is deteriorated as the temperature increases. Since the information capacity is much depend upon the light spread function than distinguishable exposure levesl, the values calculated from the equation defining the information capacity are improved as the temperature of development increases.