Present invention provides medical material sterilized by radioisotope, comprising polymer composite using in living body, containing multifunctional triazine compounds at weight ratio range of 0.01 to 20 weight percent to the polymer. The present invention shows the fabrication of polymer composite having good heat and radiation resistance, by preventing heat molding record and irradiation on sterilized processes from deteriorating molecular weight caused on heat and radiation decomposition of the polymer. It is possible that the polymer composite is applied for the medical field of decomposable and bio-absorbable polymers and even bio-nonabsorbent polymers such as suture of operation or bonding agent for broken bone as a result. Furthermore, it is possible that the polymer composite is applied for not only medical material but also food wrapping material of industrial use.