We studied plant macrofossil assemblages from the last glacial deposit below the Aira-Tn tephra in Shika, south Kyushu, Japan to reconstruct environment and vegetation during the last glacial maximum (LGM). We took sediment samples of pollen and fossil seed analysis in the horizons between 0 and 50 cm below the AT tephra. Those sediments are peaty silt including volcanic sand. Pollen assemblages were composed of temperate conifers such as Pinus and Tsuga sieboldii Type with deciduous broadleaved trees including Quercus subgen. Quercus, Carpinus and Alnus subgen. Alnus. The sum of Gramineae, Cyperaceae, and Apiaceae occupied 70 - 90 % of total herbaceous pollen counts. The fossil seed assemblages are composed mainly wetland herbaceous plants including Carex and annual herbs such as Eriocaulon, Mosla japonica, and Setaria pumilla. S. pumilla has been considered as a prehistoric naturalized plant.Charcoal concentration was very high especially in the horizon just below the AT tephra. Composition of plant fossil assemblages indicates dominant wetland herbaceous communities with mixed coniferous and deciduous broad-leaved forest. Charcoal and dominated annual herbs show frequent disturbance by fire possibly accompanying with volcanic activity.