Abstract: The surface tensions of A.1-4.5Cu-Ce alloy and the wettability,stru- eture,bond type and bond strength of the interface of Al₂O₃/Al-4.5Cu-Ce alloy were researched by means of modem testing equipment,e.g.,sessile drop method and electronic microprobe etc..The results show that by adding Ce,the surface tension of Al-4.5Cu alloy can be reduced,the wettability and interfacial cut-off stress of Al₂O₃/.Al-4.5Cu alloy can be improved.The mechanism of Ce improving wettability is due to Ce accumulation on the interface.No interfacial reaction product is found.The interface belongs to direct bond type.