High polymer materials are used in various fields, they will be expected to increase use of severe conditions in the future. However, high polymer materials have the feature that the characteristic is easy to change by the use conditions. Therefore, to expand the range of use of high polymer materials further, it is necessary to understand the fracture characteristic by the temperature dependence. In this study, specimens are three kinds of high polymer materials that inserted crack. The crack model assumed V-notch. The experiment temperatures were assumed to be a room temperature, 0, -10, -20, -30, -40 and -50℃. The dynamic stress intensity factor K_1 was determined by using caustics method and impact three-point bending test. As a result, with a fall of the temperature, the maximum value of K_1 showed the tendency to decrease in all materials.
