Identification of blood group from dental hard tissue for the purpose of individual identification of a highly burned corpse would play a significant role in a practical legal medicine. The author conducted a study of blood group with teeth left stading at a high temperature by the method of elution test. The following results were obtained. 1. The blood identifcation from heated dental hard tissue proved to be possible. 2. In cases of heat-treated theeth at $100^{circ}C$ for 120 minutes, at $150^{circ}C$ for 120 minutes and at $200^{circ}C$ for 45 minutes for A.B.O(H) blood group, the identification of blood group was possible. 3. In case of heat-treated teeth, thermostability of blood group was found to be $150^{circ}C$. 4. The adequate surface area for the detection of blood group was 40-80 meshes.