Abstract: The direct bonding joint between cemented carbide and nodular cast iron and the indirect bonding joint by using nickel foil as intermediate layer were obtained by HIP diffusion bonding process. The structure, microhardness change and element change in the zone of bonding interface were studied by means of metallograph, SEM, microhardness and EPMA, etc. The bonding strength of joint zone made by direct and indirect bonding was evaluated and their fracture characteristics were analysed.