ABSTRACT: Late Jurassic (Oxfordian to Tithonian) radiolarian assemblages in the Southern Chichibu Terrane, Southwest Japan, were obtained from sedimentary sequences in the trench-fi ll Yoshio Formation and the trench-slope basin Ebirase Formation in western Kyushu. From seven samples, 82 radiolarian taxa (15 spumellarians and 67 nassellarians) were identifi ed. The studied sections are correlated to the Late Jurassic radiolarian zonation established for the Southern Chichibu Terrane and western Pacifi c ODP Site 801B. Most of the radiolarians were species that ranged from Middle to Late Jurassic. Only three species, i.e., Loopus nudus (Schaaf), Loopus primitivus (Matsuoka and Yao), and Solenotryma ichikawai Matsuoka fi rst occurred in the Upper Jurassic in the study sections.