Stratigraphic distribution of Japanese Quaternary proboscidean species is reviewed on the basis of tephrostratigraphy and oxygen isotope stratigraphy. The appearance and disappearance of the proboscideans in the stratigraphic sequences are as follows: Mammuthus shigensis appeared at the oxygen isotope stage 35 (1.15 Ma) and disappeared at the stage 15.5 (0.62 Ma); Stegodon orientalis appeared at the stage 15.5 (0.62 Ma) and disappeared at the stage 15.1 (0.57 Ma); Palaeoloxodon naumanni appeared at the stage 10 (0.36-0.34 Ma). This paper estimated the immigration age of S. orientalis and P. naumanni into the Japanese Islands, and the age of the land bridge formation between the Japanese Islands and the adjacent Asian Continent, based on the environmental changes of the Japan Sea during the middle Quaternary which were obtained by the analyses of ODP cores. We concluded that S. orientalis and P. naumanni immigrated into the Japanese Islands at the stage 16 (0.63 Ma) and the stage 12 (0.43 Ma), respectively.