samples of gneiss and granite from the Altyn Tagh Mountain are dated by fission track of apatite. The result yields ages from 35.6 Ma to 13.6 Ma, which suggests that the uplift of the Altyn Tagh mountain began from Oligocene and lasted till Miocene. During the early stage, the uplift rate was very low, and probably a quick uplift occurred later, which is supported by regional geology, structure evolution and sedimentary sequences. The result indicates that the local uplift of the mountain was also controlled by some NEE-trending faults within the mountain. As the uplift of the mountain was probably only related to the strike-slip of the Altyn Tagh fault, the authors hold that the initial age of the left-lateral strike-slip of the fault should have been Oligocene. Regional data also show that a large-scale regional uplift of mountains in the northern edge of the Qinghai-Tibetan plateau occurred during Oligocene-Miocene period.