The aim of this work was to determine the influence of the rate of heating of lyophilized and irradiated bone grafts on such thermal properties as mass loss and the rate of heat absorption during heating. The selected heating rates were: 5 deg/min., 10 deg/min. and 20deg/min. It was found that the mass loss at temperature range 25 degrees C to 80 degrees C for lyophilized irradiated compact bones was: 3,2 plus minus 0,6%, 2,2 plus minus 0,2%, 1,6 plus minus 0,4% for heating rate 5 deg/min., for 10deg/min. and 20 deg/min. respectively, showing that the decrease of bone mass with temperature increase is lower for higher rates of heating. Moreover, the subsequent increase followed by decrease of heat absorption along with the increase of temperature was observed. The increase of the heat absorption rate with the increase of heating rate during heating of bone grafts was also found.