Abstract: Bonding of Al-Pb alloy strips and hot dipped Al or Al-2%Si steel sheets was carried out by using hot rolling. The effects of addition of 2%Si to the bath, dipping time, thickness of the intermetallic layers and fraction of blank interfaces on bonding strength are investigated. In all cases, two different kinds of interfaces are produced; hot dip aluminized steel sheets and Al-Pb alloy strips are bonded through a mechanism of the blank and block interface bonding. The total bonding strength mainly depends on that of blank interface and the fraction of blank interfaces, and there is a linear relationship between the bonding strength and fraction of blank interfaces. The effect of Si on the total bonding strength represents the fact that though it has little effect on the bonding strength of block interface, it enormously increases the bonding strength of blank interface so that the total bonding strength grows much higher evidently. Under the given experimental conditions, it increases the bonding strength of blank interfaces six times as high as that of block interfaces for hot dipped Al-2Si specimens in contrast with four times as high as that for hot dipped Al specimens.