Some of the flags set on the traverse route between Syowa Station and Dome Fuji in the Antarctic, which were carried back to our group by the staffs of Wintering Party of the 35th Japanese Antarctic Research Expedition in 1993-95, were examined as specimens exposed in the polar regions. The fibers of original flag with a circular cross section showed flat and smooth surface, though the fiber of the exposed flags showed a weave-like shape by the disappearance of the skin parts. Such violent disruption was not observed for the flags exposed under mild weather in Nishinomiya Japan. The degradation of the flags exposed in the Antarctic was estimated in relation to the depletion of the ozone layer as well as multiplex reflection of sunshine and a strong wind from the characteristic circumstance of the Antarctic. In addition, the oligomerization on the surface of the fibers exposed in the Antarctic was observed by scanning electron microscopy. This was suggested to the recrystallization formed under the influence of intensely ultraviolet irradiation, multiplex reflection of sunshine and water
