Abstract: Lacustrine sediments in Bulunkou area of West Kunlun Mountains in Akto County is linearly distributes along Muji River in nearly SN-NW direction,it is obviously controlled by neotectonics and forms early sedimentary formation in linear fault zones.Through 1∶50 000 regional geological survey,it is found that this formation is the main body of nowaday high－based Muji River terrace.Trough some relevant sections,tt is the first time to acquire its OSL(optically stimulated luminescence) dating age of (55.5±8.6)~(94.8±9.7)ka,which can provide reliable reference for the study of neotectonics in the area.

Key words: Optical stimulated luminescence (OSL) , Late Pleistocene, Neotectonics, Geological significance