Late Permian (Wuchiapingian-early Changhsingian) radiolarian fossils such as Albaillella cavitata, A. protolevis, Follicucullus scholasticus, and Triplanospongos musashiensis were discovered in felsic tuff and tuffaceous mudstone from the Kurosegawa Belt on Shima Peninsula, Mie Prefecture, Southwest Japan. Strata containing felsic tuff and tuffaceous mudstone show coherent, non-deformed facies and have an apparent thickness of ca. m. Although these strata were formerly interpreted as Lower Cretaceous forearc deposits of the Matsuo Group, based on lithofacies similarities, there is now little doubt that they represent a coherent late Permian sequence. Such a sequence is reported from Kii Peninsula (part of which is Shima Peninsula) for the first time, and it appears to have a significant regional extent, stretching from Kyushu Island through Shikoku Island to Shima Peninsula. The coherent late Permian sequence on Shima Peninsula can be chronologically correlated with the Doi Group and parts of the Ichinose Group on Shikoku Island, and also with parts of the Kuma and Kozaki formations on Kyushu Island.