This paper treats of the biostratigraphy and correlation of the foraminiferal zones of the Carboniferous Hina Limestone in Okayama Prefecture, western Japan. The Hina Limestone is divisible into three foraminiferal zones, namely, the Endothyra-Mediocris zone, the Eostaffella-Millerella zone and the Pseudostaffella-Profusulinella zone in ascending order. The Endothyra-Mediocris zone is characterized mainly by Endothyra-similis, E. exilis, E. irinae, Endostaffella sp., Eoendothyranopsis sp., Planoendothyra sigma and Mediocris mediocris. Most of them are discovered for the first time in the Hina Limestone. The Eostaffella-Millerella zone is characterized mainly by Eostaffella ikensis, E. akiyoshiensis, E. kanmerai, E. mosquensis, Millerella toriyamai and M. marblensis. The Pseudostaffella-Profusulinella zone is composed of Pseudostaffella minuta, Nankinella yokoyamai, Profusulinella sp. and others. These three zones are regarded as ranging in age from the late Osagean to the middle Atokan in North America, and the early Visean to the late Bashkirian in Russia. Based on this study, the geological structure of the Hina Limestone can be elucidated.