Efforts are made to draw some characteristics of the Neogene (kuroko-type and hydrothermal veintype) mineralization in the Sanin Green Tuff region compared with equivalent activity in the Inner Zone of northeast Japan. In the Sanin region, the Onnagawa Stage is likely to be the major mineralization epoch and some of the deposits seem to be related to the Funakawa Stage, whereas the mineralizations in northeast Japan are known to occur mainly in the Nishikurosawa and Onnagawa Stages. In general, the main stage of mineralization in the Sanin region is characterized by ore mineral assemblage chalcopyrite-pyrite with quartz-sericite-chlorite as gangue assemblage. While the base-metal deposits of both regions are much alike in several aspects including oreand gangue-mineralogy and fluid inclusion systematics, absence of pyrrhotite and arsenopyrite in the Sanin ores makes them sharply contrasted with the ores from northeast Japan. It seems that the Sanin ores were formed in relatively limited depositional conditions defined by pyrite-bornite-chalcopyrite univariant assemblage and less than 3 mol.%FeS in sphalerite coexisting with pyrite, while much varying physicochemical environments existed in the Neogene mineralization field of northeast Japan.