The Qaidam Basin, a Cenozoic petroliferous basin, lies on the margin of the northern Tibetan Plateau. It records a lot of information about uplift and expansion of the northern Tibetan Plateau. High resolution satellite images, geophysical data and magnetostratigraphy chronology data are used to analyze the mechanism and development of fold belts in the western Qaidam Basin. It reveals that: (1) Hongsanhan, Jiandingshan-Heiliangzi, Nanyishan and Youshashan fold belts are all composed of asymmetric vertical or homoclinal folds related to thrusting, of which, just as the Jura-type fold, the tight anticline alternates with gentle syncline, indicating a decollement structure at depth; (2) Folds with gentle SW limb and sharp NE limb like Hongsanhan and Jiandingshan-Heiliangzi fold belts are formed by northeastward thrusting; the southwestward thrusting creates a fold with sharp SW limb and gentle NE limb, like Youshashan fold; the relative symmetric Nanyishan fold belt results from NW-SE thrusting; (3) The growth strata on the Hongsanhan, Jiandingshan-Heiliangzi and Nanyishan fold belts are Xiaganchaigou, Shizigou and Qigequan formations, with the high-resolution magnetostratigraphic age of similar to 39. 5Ma, similar to 8. 2Ma and similar to 2. 5Ma, respectively. The initial time of growth strata presents the initial formation age of the fold belt as well as the age of thrusting. A series of similar drainage systems on the Youshashan fold belt is bending along the regional tectonic strike. This implies that the ongoing growth is taking placed in the Youshashan region. The SN vertical Hongsanhan fold, along with dome-like superimposed fold in the western Qaidam Basin, indicates a EW compression associated with the strike-slip of the Altyn Tagh fault; (4) Based on the tectonic geomorphology, growth strata, seismic reflection profiles and magnetostratigraphy,, the main fold belts in the western Qaidam Basin result from southward propagating during Cenozoic. The backward propagation model indicates that Indian-Asian collision stress has reached the northern part of the Qaidam Basin at similar to 40Ma, formed the Hongsanhan thrust-fold belt. With the continuous compressing, Jiandingshan, Nanyishan and Youshashan fold belts come into being one by one, of which, the latter two fold belts, the composition of the present "Yingxiongling", are formed under the strong S-N compression since similar to 2. 5Ma. Since similar to 8Ma, the intensive activity of the Altyn Tagh fault had affected the entire Qaidam basin.
