Diffusion joining of beryllium and HR 1 stainless steel with interlayer by hot isostatic pressing(HIP) (Cu layer or Cu/Ni layer) was investigated in this paper. The basic evaluations of bonded joints were made through metallurgical observation, SEM, AES, XRD, MPM and tensile testing. For Be/Cu/316L joint, Cu interlayer blocks the diffusion of Fe into Be, but Ni is gathered at Cu/316L interface and the crack is formed at this field. For Be/Cu/Ni/316L joint, the diffusion depth increases further. Change of Composition, mechanical property with distance in diffusion zone is smooth, and the tensile strength is about 50 MPa.