CFRP is currently being applied to various machines and structures, but compared to metallic materials, non-destructive testing and integrity evaluation methods are not yet well established. Even with the same material and the same application under external force, the strength and the damage mode are changed when stacking sequences of CFRP are changed. There are various damage modes in CFRP, such as fiber breakage, delamination, etc., but non-destructive testing methods have been established for only a limited number of damage modes. In our laboratory, we are developing technologies to control the fracture so that the damage is easy to find by nondestructive inspection, taking into account the loads that may act on several CFRP structures. We are also developing crack arrest system with online monitor for CFRP adhesive joints.