A comprehensive survey of advanced materials for civil aircraft structures from the research point of view would of course include new aluminium alloys, titanium alloys, steels, composites, transparency materials and adhesives. Such a survey is, however, out of the question within the scope of this part of the paper and attention will therefore be concentrated on fibre-reinforced composite materials, partly because as a primary structural material they are now widely recognised to offer much the greatest prospect for really substantial improvements in structural efficiency (weight saving of the order of 30%, for example Fig. 1.1 shows comparative specific properties of various structural materials) and for lower costs, and partly because to realise these improvements a wide and in many ways novel range of research problems throughout the whole spectrum of material development and characterisation, design, fabrication and testing needs to be solved. It will nevertheless be possible, even with this limitation, to do no more than to give a brief sketch of the present position in some of the main research areas, primarily from the UK point of view.