Abstract: Based on the study of basin infilling and tectonic evolution,this paper demonstrates that the basin is formed in the local extensional faulted subsiding generated by strikeslip structural activity.The sinistral strike-slip activity of the Xiaojiang fault with trend of N-S has led to the tectonic formation and development of the pull-apart basin,and after the basin formation the deformation of structural reversion was developed due to the same activity.In the paper the geodynamic models for the basin formation and its structural reversion is esta blished.