The current situation with regard to the use of high-performance composites is one of seeking a reliable means of characterizing the fundamental properties and/or behavior of composite materials. The employment of such materials in vi­ tal structural applications require criteria as part of the materials selection and design procedures. However, the principal limitation of the many currently available procedures, most of which were borrowed from the metal i"ndustry, is its intrinsic restriction to single phase materials. They cannot adequately ac­ count for the variations in the constituents or structure of the composite that can have a significant influence on its gross behavior. Although a considerable amount of research has been conducted in the past with the objective of under­ standing composite material behavior, for the most part, the research efforts tended to cover too wide a spectrum of problems with little penetration into the fundamental aspects. For this reason, the investigators in this field have long felt the need to bring together a small group of experts to review the fun­ damentals, discuss the problem areas, and display the current developments. The USA-USSR Sympo~~ on the f~ct~e 06 Compo~~e Mat~ was organized for this purpose. There is the additional need to share this information with the new­ comers to the field as well as the oldtimers. This is accomplished by publish­ ing the symposium proceedings contained in the present volume. A Russian trans­ lation of the papers in this volume will also be made available.