Abstract: The basic characteristic of 120 ℃ thermoluminescence peak of iceland spar was studied. The experimental result indicates the longevity of 120 ℃ thermoluminescence peak of iceland spar is about 2 h under 30 ℃. The thermoluminescence peak moves to the high temperature when the heating speed increasing. The intensity of 120 ℃ thermoluminescence peak of iceland spar is directly proportional to radiation dose under 15 Gy.