Explosive welding process is one of the effective methods in order to weld two dissimilar materials. Aluminum-steel composite was undergone heat treatments at temperatures between 2000C-5000C. In this study, the effects of explosive ratio and stand-off distance on the shape of the interface were studied. Moreover, the effects of various heat treatments on the interface strength are studied. The study shows that the type of the explosive, the magnitude of explosive ratio and standoff distance produces various interfaces with or without intermetallic compounds. The results show that effects of heat treatment on the aluminum-steel bond strength is depended upon the type and microstructure of straight, wavy and continuous melt produced at the interface. Moreover, the study shows that heat treatment gives rise to produce the brittle intermetallic compound of FeAl3 which lowers the weld strength. Having produced the smooth interface would reduce the heat treatment effects on lowering the weld strength.