range between holding temperature and cooling temperature. Furthermore, the measurement of err(X) and e~r by the simplified optical method is as easy as the ordinary two-dimensional photoelastic method, and more expedient than the layer-removal method which is essentially a destructive method. Therefore, we are confident that the simplified optical method in which the proposed fundamental equations are used is very effective for the experimental evaluation of residual stress and residual strain by rapid cooling in thermosetting resin strips.