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The sequences of fluvial terraces in the YaziSpring Stream are signs of the stepwise uplift of the KunlunMountains in the northern part of the Tibetan Plateau sincethe Late Pleistocene. Geomorphic and sedimentary featuresof the terraces reveal that they have resulted from the phasedtectonic uplift and the consequent river incision in thenorthern plateau. Using the method of Single-aliquotRegenerative-dose (SAR) Protocol and Radiocarbon 14Cdating, the deposit ages of three-grade terraces were ob-tained, which are 57.5, 12.8 and 5.7 kaBP, respectively. The features and ages of terraces reveal that the incision rate of the stream accelerated at the beginning of the Holocene. The incision rate changed suddenly at 12.8 KaBP, from 0.43±0.07 mm/a to 1.59±0.55 mm/a. This implicates that uplift of the Kunlun Mountains is intensive at the first onset of the Holo-cene, corresponding to the obvious change of slip-rate on the Altyn Tagh Fault. But its uplift rate is much lower than that of the latter, which suggests that growth of the northern mar-gin of the Tibetan Plateau is stronger than its interior.