Thirty-five papers were presented at the International Symposium on Photoelasticity, Tokyo, 1986, representing fifty-five authors. Eighteen of these papers were presented by Japanese photoelasticians and seventeen by leading foreign authorities from eleven countries (Austria, Canada, Czechoslovakia, F.R. of Germany, France, Greece, India, Switzerland, UK, USA and USSR) • This is the first symposium on photoelasticity of international scope held in Japan. The primary objectives of this symposium are to help bridge the gap between photoelastic researchers around the world, to promote mutual understanding and communications and to facilitate exchange of newly acquired knowledge in theories and techniques. In addition, it is important that these valuable results are communicated effectively to engineers who can apply them in practice in industry. The papers presented at this symposium cover all branches of photo­ elasticity in a broad sense, including, in addition to long estab­ lished photoelasticity, newly developed moire, interferometric, and holographic photoelasticity, caustics and speckle. Therefore, from an optical stress analysis perspective this volume is the latest comprehensive collection of photoelastic expertises.