Abstract: The principle for choosing proper interlayer materials to bond dissimilar metals was discussed. An appropriate interlayer was designed and bonding experiment was carried out to join stainless steel panel with aluminum alloy honeycomb core. The function of interlayer was investigated by analyzing the interface microstructure and examining the joint strengths. The effect of processing parameters on the interface microstructure and liquid diffusion bonding was also discussed. The results show that good wetting and spreading properties in the interlayer were attained so that firm metallurgical bonding between stainless steel and aluminum was obtained.