From Mesozoic, evolution of the North Tarim Uplift underwent three phases: upthrusting, tectonic inversion and ramp of forebasin, corresponding to the strong, weak and strong tectonic evolution phases of the Kuche Foredeep respectively. The negative inversion structures in the North Uplift of Tarim basin formed during the Cretaceous Tertiary. In the stage of pre-Cretaceous, the Kuche Foredeep and Northern Depression developed . Because of strong compression stress, the lithosphere bent and two groups of back thrusts formed to achieve shortening in the North Tarim Uplift. During tectonic tranquility period(K-N1j), since the lithosphere adjusted and the former forebulge locally extended, two back-thrusts slided along the former thrusts, the movement resulted in the negative inversion structures. After Miocene,because the lithosphere flexural rigidity increased, flexural crest migrated out of the Northern Uplift. Consequently, the Northern Uplift became a part of foredeep, so the negative structures not only still existed, but also had a tendency to become wider. The reason of the extensional stress field may be attributed to the chang of wave crest and wavelength of the lithosphere syn flexure.