Inviscid melt-spun calcia-alumina (CA) fibre-reinforced aluminium 7075 alloy matrix composites were produced at 700 and 927 degrees C by using a melt-infiltration method. Interfacial wetting and chemical reaction of the composites were investigated by using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The composites processed at 700 OC showed interfacial wetting and magnesium accumulation at the interfacial region. The composites processed at 927 degrees C showed the formation of a 15 mu m thick interphase region as well as excellent interfacial wetting. EDS analysis gave averaged compositions of this interface region at 63.5 at % Al and 31.5 at % Mg, which corresponds to-the composition of spinel, MgAl2O4. The formation of spinel at the interface was confirmed by XRD analysis on the CA fibres separated from the composites.