Fusuline fossils are uncommon and are generally poorly preserved in rare limestone blocks within a Jurassic accretionary complex in the Kambara Mountains of Niigata Prefecture, Japan. The poor preservation of fossils in this area is due to the thermal effect of intrusion of Late Cretaceous to Paleogene granites. Middle Permian (Guadalupian) fusulines such as Yabeina kaizensis Huzimoto, Neoschwagerina sp., Chusenella sp., Dunbarula sp., and Sichotenella ovoidea (Sosnina) were obtained from three limestone float boulders in the western Kambara Mountains. These fossils are paleobiogeographically important and will be used in further research to reconstruct the oceanic plate stratigraphy of the Kambara and other mountains along the Japan Sea side of northeast Japan.