The possibility of experimental model analysis in which stress birefringence is utilized for the simple and accurate evaluation of the tensile stress distribution in short-fibers embedded in composites has been investigated. For this purpose, a birefringence-free polymer blend is used as the matrix resin to avoid any influence of stress birefringence. When the stress applied to the composite is low, the experimental results agree with the theoretical estimates; however, as the stress increases, a slight deviation is detected.