This paper aims, on the basis of marine and terrestrial palynology (dinoflagellate cysts and pollen), to discuss ages, paleovegetation, and paleoclimate of Tertiary sections from the Makarov, Aleksandrovsk-Sakhalinskiy and Schmidt Peninsula areas, Sakhalin Island, Far East Russia.<BR>The present study of dinoflagellate cysts has drawn good age constraints on most of the sections as follows: upper Lower? to Upper Oligocene (the Gastellov and Kholmsk-Nevel'sk Formations in the Makarov area and most of the Tumi Formation in the Schmidt Peninsula area), lower Lower Miocene (the uppermost part of the Tumi Formation and the lower part of the Pili Formation in the Schmidt Peninsula area) and upper Lower to lower Middle Miocene (the Kurasi Formation and the First Member of the Maruyama Formation in the Makarov area and the Sertunai Formation in the Aleksandrovsk-Sakhalinskiy area).<BR>Pollen assemblages from the upper Lower to lower Middle Miocene sediments, the Verkhne Due Formation and the lower part of the Kurasi Formation in the Makarov area, and the Verkhne Due and Sertunai Formations in the Aleksandrovsk-Sakhalinskiy area, are correlative to those from sediments in northern Japan that yielded the Daijima-type flora. Those Sakhalin assemblages indicate a temperate paleovegetation similar to that indicated by coeval assemblages from the northern part of Hokkaido. This suggests that the latitudinal gradient in paleovegetation/paleoclimate was relatively minor between Sakhalin Island and Hokkaido during the late Early to early Middle Miocene.