Abstract: The spreadability of Zn-Al filler metals on 3003 Al alloy and 304 stainless steel substrate, and mechanical property and microstructure of 3003 Al alloy/304 stainless steel joints were studied by filler metal spreading test and lap brazing test. With the increase of Al content, the spreadability of Zn-Al filler metal on 3003 Al alloy substrate and 304 stainless steel substrate increases first then decreases.The best compositions are Zn-15 Al for 3003 Al alloy substrate and Zn-10 Al for 304 stainless steel substrate, respectively. The spreadability on 3003 Al alloy substrate are more excellent than that on 304 stainless steel substrate. With the increase of Al content, the shear strength of 3003 Al alloy/304 stainless steel joint brazed by Zn-Al filler metal increases firstly then decreases. When the Al content is 10 wt %, the joint strength reaches the highest of 132. 62 MPa, while the Al content further increases,the thickness of the Fe₄ Al₁₃intermetallic compound layer at the 304 stainless steel side interface increases, and it is easy to cause stress concentration and initiation of crack, which makes the joint strength decrease. Considering comprehensively, the 3003 Al alloy/304 stainless steel joint brazed by Zn-10 Al filler metal has the best properties.