When bonded dissimilar materials such as ceramics/metal are designed for enhancing bonding strength, it is desirable to design interface shapes which make the stress singularity that occurs near the edge of the interface disappear or decrease. However, the desirable design for interface shapeswhich was based on theoretical analysis indicated the possibility of the relaxation of residual stress. Therefore, data which were based on the experimental result were required, to obtain the guiding principle of joint design to achieve a high-strength joint. In this work, to clarify the desirable interface shapes which relax residual stress or enhance joint strength, the joint strength was evaluated. A comparison between experimental results using TiB₂-Ni joint and results obtained using theoretical and finite-element methods were performed.