This overviews the interface microstructures in ceramic fibers/whiskers reinforced aluminum alloys and discusses how we can control those interfaces in order to achieve optimized properties for composites. Among many factors influencing on properties of composites, breaking oxide films on aluminum powders, getting interfacial binding and controlling reaction are three of the essentials. For breaking oxide films, alloying elements such as magnesium and silicon have great effects. One should select an optimized alloy for the matrix of a composite. Once surface films are broken and the flesh surfaces of reinforcements and a matrix alloy contact each other, a tight bonding at an interface can be achieved easily because of the high activity of aluminum. One must control the interface reaction. Two interfaces are shown as the examples for controlling interfaces to obtain better properties. Several methods are proposed for the interface control to improve high temperature properties of aluminum matrix composites.