Abstract: Yingen-Ejinaqi Basin, Yin-E Basin for short, is a Meso-Cenozoic basin on the southern margin of the central Asian orogenic belt. During our 2017 field geological investigation, Early Jurassic and Late Quaternary extensional structures were found on the western margin of the Yin-E Basin. The Early Jurassic extensional structures are a series of normal faults striking NNW-SSE. They are the syn-sedimentary faults of the Lower Jurassic strata. These normal faults and the NNE-SSW striking normal faults in the Yin-E Basin constitute a conjugate system indicating the maximum extensive stress in N-S direction in Early Jurassic. They are the post-orogenic structures of the central Asian orogenic belt. The Late Quaternary extensional structure is a graben composed by two normal faults dipping to each other. The normal faults strike in E-W direction. They represent possibly a tectonic pause between two successive thrust pulses of the far-field effect of the India-Asia collision.