Abstract: The Gediz Graben basin, one of the youngest and important structural elements of the Western Anatolia,has an evolutionary history with markedly geologic and geomorphologic phases during the Quaternary.The old and actual Gediz River, running since the beginning of the Quaternary, and various sized lakehave deposited their sediments during a tectonic-controlled basin evolution processes developed in N-Sextension regime.In this study, sedimentary facies, environmental properties and characteristics of the Gediz basin changedby synsedimentary tectonics during the early and late Quaternary are explained. Also it is emphasized thatthe joining adventure of the river with the sea was probably lived in the middle of the Holocene, and thegeologic and geomorphologic evolution of the river in the Quaternary is interpreted.