Changes of the serum protein concentration were examined in the following groups of rats: a) those continuously irradiated at a dose rate of 1 Gy/day up to a total dose of 7 Gy [1R], b) burned with dry heat of 110 °C for 20 s on a 1590 mm2 area of body surface [B], c) subjected to both (irradiation and thermal injury) treatments [MIX], d) an intact control group [C]. It has been ascertained that the dynamics of change in serum prealbumin, Ai-macroglobulin, haptoglobin and haemopexin in all experimental groups were in principle similar from the 7th day after the onset of irradiation. However, compared to the control group, a significant difference was observed particularly after thermal damage and after the effect of both treatments. Alterations in serum protein concentrations after irradiation alone had only a temporary effect.