In the usual manner objective tone reproduction curves are obtained graphically from flare curves, photographic characteristic curves of negative films and photographic papers. The author attempted to obtain these curves calculatively by using mathematical models. Mathematical models for the flare curve, the photographic characteristic curves of the negative film and the photographic paper were established. After numerical analyses on parameters employed in mathematical models from experimental data, density values of prints were calculated from values of parameters by using mathematical models. Caluculated density values of prints were compared with experimental ones. Consequently it was found that good fitness was shown in highlight and midtone regions.