Abstract
This paper discussed the optical properties of the so-called Tamamushi Fabrics (iridescent fabrics) by the use of a gonio-photometer.
The results obtained are : 
(1) The factors governing the optical properties of the Tamamushi Fabrics are considered to be the surface structure of the fabrics, fabric construction, glosss and combination of the colors of warp ends and filling yarns.
(2) The reflection light of the Tamamushi Fabrics should be considered by separating it into the specular components and diffuse components.
(3) The optical properties of warp ends and filling yarns have an important bearing on the iridescence of the Tamamushi Fabrics.
(4) The change of the color on the Tamamushi Fabrics should be discussed from the gonio-photometric reflection curves obtained from the monochromatic light resembling the colors of the warp ends and filling yarns.
(5) The larger the hue difference between the warp ends and filling yarns, the larger the change of color on the chromatic diagram.