Destruction is a usual phenomenon in the trouble of rubber and plastic products, in particular fatigue fracture is frequently found in the case of vulcanized rubbers. Observation of fracture surface, that is fractography, is not reliable technique in the field of rubbers and plastics, even though it is well known method as the first step of accident analysis. Supporting evidence, such as results of surface analysis on the fracture and molecular weight measurement of damaged part, is necessary as well as the observation of fracture surface. There are some techniques against the fatigue fracture, for instance, increasing the radius of curvature of products and the amount of antioxidants.