Fission-track analysis indicates that the uplifting process of the northern segment of Altyn Tagh fault zone at the Aksay-Dangjin Pass since the Cenozoic can be divided roughly into three stages,43. 6~24. 3Ma,19. 6-13. 6 Ma and 9~7 Ma BP. The tectonic uplift of the Altyn Tagh fault zone related to the sinistral strike-slip movement in the Cenozoic occurred during 19. 6 -13. 6 Ma,and the uplift became rapid in 9~7 Ma BP, thus forming the Altun Mountains. The uplift was initiated in the early -middle Cenozoic (43. 6~24. 3 Ma) at a rate of 0. 227 mm/a;the second uplift occurred in the middle Cenozoic (19. 6~13. 6 Ma) at a rate of 0. 35 mm/a; and the third took place in the late Cenozoic (9-7 Ma)at an average rate of 0. 94 mm/a. The middle-late Cenozoic activation model shows that the fault zone appears to have undergone uplifting and sinistral strike-slip movement during 19. 6~13. 6 Ma; later it had sinistral strike-slip and thrust characters, giving rise to pull-apart basins after 9-7 Ma. The fission-track age of apatite from the eastern part of the Altyn Tagh fault zone is older than 30 Ma and that of apatite from the northern margin of the Qaidam Basin is 43. 6-24. 3 Ma, dif- ferent from the apatite fission-track ages of the Altyn Tagh fault zone. The age data of the samples taken from the Altyn Tagh fault zone on the northern margin of the Qaidam Basin indicate that the sinistral strike-slip movement along the fault zone seems not to have affected the uplifting of the northern margin of the Qaidam Basin. The middle-late Cenozoic tectonic uplift and sinistral strike-slip movement of the Altyn Tagh fault zone were related to the collision between thelndian and Eurasian plates and the tectonic uplift of Qinghai-Tibet Plateau.