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On the basis of field survey, microscope sighting, TL dating and scanning electron microscope analysis, the characteristics of Quaternary deposits near Songjianghe Town on the west slope of Changbai Mountain are analyzed and described. There were two phases of volcanism during Mid-Late Quaternary. One occurred before 15.22 × 104 aB.P. and the other happened between 14.27 × 104 aB.P. and 1.41 × 104 aB.P. Volcanism is a landform-making process which makes the rough relief in the studied area become higher and higher. Flow water is a main erosion agency and it cuts into the basalts making river valleys. The Quaternary fluvial deposits distributed on terraces first come from the weathered debris of basement rocks, then they are transported and deposited by flow water. After 1.41 × 104 aB.P, the river water quickly cuts into the newly formed basalts making a deep valley. Volcanism in the studied area is a main landform-making event in Mid-Late Quaternary.