The temperature dependence of development rate of AgCl emulsion was estimated from the developed silver vs. development time curves calculated from current-potential curves of anodic reaction of ascorbic acid developer and of cathodic reaction of AgCl which were measured on gelatin coated electrodes, and compared with experimentally measured one. The calculated “activation energy ” was in good agreement with the measured energy. It was discussed that the “ activation energy ” of development would be an apparent activation energy which differed from usual activation energy.