ABSTRACTA high performance composite material consists essentially of aligned, continuous carbon, glass, aramid or ceramic fibres in a thermoset or thermoplastic matrix. The types, advantages and disadvantages of the various matrices available which can operate at elevated temperatues are described, particular attention being paid to the work of fracture. The main fabrication methods for both types of material are outlined and Some fracture properties for composites together with illustrations of the effects of short term temperature exposure on the modulus, strength and interlaminar shear strength, are provided.