Abstract: The diatom and foraminifera analysis is made for the samples of Late Wurm sedimentary layers determined by palynology,radiocarbon dating and paleomagnetism from 14 cores in the estuarine plains and sea area of the western Taiwan Strait.The results show that the sedimentary layers at that time in the sea area are all marine sediments and those in the estuarine plain are composed of alternate marine and terrigeneous strata.Accordingly,an idea is proposed by authors that the Taiwan Strait in Late Wurm glaciation belongs to the shallow sea sedimentary environment with a water depth of 30-50 m.Thus a phenomenon inconsistent with the eustatic sea-level rise and fall caused by global climatic cold-warm replacement is suggested to be due to the differential crustal movement.During Late Wurm glaciation,the Taiwan Strait is subjected to the crustal intermittent falling so as to keep a shallow sea environment.