In modern society, we can see various large structures such as large buildings, ships, bridges that have been constructed using metal, polymers and polymer alloys. Many other new materials are being developed and invented in the world. These materials are made on automatic line systems in factories. These are tested under the rigorous and sever conditions, and shipped on demand. After rigorous testing, however, materials often contain cracks, holes or inclusions. The intensity stress generates on top of the crack and may cause accidents. Holes or inclusions in the material have negative effects on the rigidity and the safety. Many researchers use the high polymer materil for the purpose of the analyzing about cracks, holes and inclusions. The crack, the empty hole and the inclusion become of one of the cause of the fracture and the accident. The authors think that the various problems about cracks, holes and includes are not studied enough. They tried to examine the relation ship of the details of stress intensity factor of the high polymer materials by means of the caustic method and the photoelastic method. This paper discusses the causes and effects of mutual interference of cracks, holes and inclusions in the materials.