Using an already developed thermo-mechanical method, temperature ranges were determined of thermal coagulation of myofibrillar and sarcoplasmic meat proteins. Those proteins as indicated in the first sentence were determined in meat of 5 fish species (12 samples of raw material) and in beef and pork [9]. Moreover, a limiting temperature of denaturation of all muscle proteins was determined. Temperatures necessary to heat up meat (ca. 77⁰C) so as to get complete denaturation of all the meat proteins were similar. However, despite this fact, it was proved that the temperature of complete coagulation of myofibrillar proteins (without free actin that sporadically occurred in the samples tested) varied and was ca. 48^oC as for saltwater fish, ca. 51^oC as for freshwater fish, and ca. 56^oC as for slaughter animal meat. The period of fish spawning produced no significant effect on the temperature range of individual protein fractions coagulation, but it depressed peaks of the sarcoplasmic protein fraction.