Photocalorimetric measurements using thermistor is applied to study the heat generation by nonradiative processes in erythrosine and eosin dyes in epoxy resin. Photocalorimetric spectra of them agree with photoacoustic ones in low concentration and the former are different from the latter in high concentration cases. The light intensity dependence of heat generation of both dyes in epoxy resin was linear although the optical absorption spectra showed nonlinear character. The experimental results were analyzed by four-level model to show that the difference of light intensity dependence between photocalorimetric intensity and optical absorption was based on triplet-triplet transitions.