Interpretation of the development process and forming mechanism of Well Yubei 1 anticline belt in the Tarim Basin is an important part of study to map the carbonate reservoirs.Analysis of faults and axial planes of the anticlines reveals that two structural styles occur in the study area.One is positive flower structure which runs through the anticline belt in N-S direction.The other one shows significant difference in structural style between upper and lower structural layers.The upper layer is a symmetry anticline and is controlled by a high angle strike slip fault.The lower layer is a dissymmetry anticline and is controlled by a thrust fault developed along the Cambrian gypsiferous mudstone layer.Well Yubei 1 anticline belt was finalized in the mid-Caledonian period

and experienced at least two regional deformations in the late-Caledonian and late-Hercynian.However

the anticline belt changes along the inclination of the anticline

and is converted from a thrust structure to a strike-slip structure in N-S direction.The anticlines are most highly developed at the intersection of two main faults.The Cambrian gypsiferous mudstone was deposited at its core

resulting in a shear-compression anticline.On this basis

we believe that the Ordovician carbonate sequence not only experienced two stages of uplifting and erosion in the Caledonian and early Hercynian and the high angle and low angle fractures developed in the anticlines formed by shear-compression all which provided good conditions for the karstification.