The fluctuation of the East Antarctic ice-shect (EAIS) margin and relative sea-level change since the last glaciation are discussed from the stratigraphy and TAMS 14C ages of raised beach deposits in the northern part of the Soya Coast.The beach deposits reveal two marine sediment layers with in situ fossil shells of Laternula elliptica, and an interbedded fluvial sediment layer. The l4C ages of fossils in the lower, older marine beds ranged from 36 to 43 ka, and in the upper, younger beds from 4.9 to 5.2 ka without reservoir correction. Neither marine layers nor in situ fossil shells were disturbed by ice-sheet loading or scouring. The interbedded fluvial sediments appear to have been deposited by a stronger fluvial process than present meltwater activity in the area. These facts lead us to the following conclusions: (1) marine transgression occurred during the last interstadial around 40 ka or the Last Intcrglacial, and in the Holocene around 5 ka: (2) the EATS possibly retreated from the northern Sôya Coast prior to the Last Glaciol Maximum (LGM); (3) the fluvial process may have occurred during a period of low sea level which may have been a warmer period than the present, probably during the late-Glaciol to postglaciol age; and (4) the EAIS did not rcadvance over these sediments during or since the LGM.