This volume contains 35 contributions presented at the IUTAM Symposium on Microstructure--Property Interactions in Composite Materials. The subject of the Symposium was the quantitative description of microstructures and linking this description to physical properties of composite material systems. The contributions emphasized the significance of the microstructure morphology in understanding the nature and origin of a multitude of properties, such as viscoelasticity, plasticity, strength and fracture for a variety of polymer, metal and ceramic-based composites. The volume will be of interest to specialists in the mechanics of solids, materials scientists and engineers investigating the use of advanced materials in structural applications.