Abstract: The shape,microstructure and the mechanical properties of SiC_p/Al composite joint by electron beam welding (EBW) were investigated.The results show the main defects in EWB of SiC_p/Al are poor weld appearance with the groove covered by particles.The weld consists of gray Si,dark gray needle phase of Al₄C₃,which generate from interfacial reaction,and AlSi eutectic phase.The brittle fracture occurs at the brittle zone formed by the above three phases.The high hardness of fusion zone is quite different from that of weld.The average highest tensile strength of the joint is 73 MPa,which is 41% of that of the SiC_p/Al base metal.