The central and western North China and the NE margin of the Tibetan Plateau connects east China and west China, which are dominated by horizontal extension and compression, respectively. This study area consists of a variety of tectonic units, including the Songpan-Garze block and Qilian orogenic belt, which are terranes of the northeastern Tibetan Plateau; the Alxa block, the Ordos block and its surrounding grabens and orogenic belts thecentral and western North China; and the mid-south Central Asian Orogenic Belt (CAOB). To the west of the study area, the ongoing convergence between India and Eurasia plate caused the uplift, crustal thickening and lateral escape of the Tibetan Plateau. To the east, the westward subduction of the Pacific plate to the Eurasian plate strongly affected the tectonic movement of the plate margin and interior. Here seismic activity is strong and tectonic structure is complex. Thus, the study area provides a unique nature laboratory for understanding continental interiors and lithosphere' s deformation. Due to the intrinsic linking between anisotropy, finite strain and tectonic process, seismic anisotropy studies have been used widely to constrain on deformation pattern of the crust and lithosphere mantle during an orogenic process. In this study, Based on the polarization analysis of teleseismic XKS (SKS, SKKS and PKS) waveforms recorded at 480 stations from 3 temporary seismic array deployed in the central and western North China and the northeastern Tibetan Plateau, the fast-wave directions and delay times were measured by using the grid searching method of minimum tangential energy and stacking analysis, and we used the 480 new shear wave splitting observations from dense temporary seismic array and 987 published results to map out variations in the deformation of the study area. The comparative analysis of anisotropy with surface deformation, geological structure and lithospheric structure shows that, on the whole, the value of delay time in the Ordos block is less than that in its margins and other tectonic units, it shows the value of delay time in the stable units is less than that of the active units, it also shows weak anisotropy and lithospheric deformation, indicating the anisotropy of the stable Ordos block is possibly caused by "fossil" anisotropy frozen in the ancient North China Craton ( NCC). However, the anisotropy of the parts of Ordos block near its margins is consistent with that of their adjacent margins, showing the lithospheric deformation in the parts of Ordos block is affected by the tectonic activity of its adjacent margins. The fast wave directions trend NW-SE in the northeastern Tibetan Plateau, and western margin of the Ordos block, and rotate to NNW-SSE in northern margin of the Ordos block, indicating the NE-trending push of the Tibetan Plateau has caused NW-SE-trending and NNW-SSE-trending lithospheric extension in the northeastern Tibetan Plateau, the Alxa block, the western and northern margins of the Ordos block. In the Qinling orogenic belt between the rigid Ordos block and the rigid Sichuan basin, the E-W or NWW-SEE trending fast wave directions are parallel to the tectonic strike of fault, orogenic belt, collision boundary and absolute plate movement, it indicates that the Qinling orogenic belt is not only the extrusion channel of the lithospheric material of the Tibetan Plateau, but also the eastward asthenospheric mantle flow channel. There is an overall counterclockwise rotation pattern from west to east of the fast wave directions around the southern Ordos block that are oriented NW -SE in the Liupan mountain of the southwestern margin of the Ordos block, to E-W in the Weihe graben of the southern margin, and then to NEE-SWW in the Taihang mountain of the southeastern margin, we conclude that there may be an asthenospheric flow around the southern Ordos block with thick -root, which produces the observed anisotropy with the simple left-lateral shear deformation in lithosphere, and they drive together the counterclockwise rotation of the Ordos block. The central North China is the transitional zone between east NCC and west NCC. Here the anisotropy is relatively complex. In the east part of the central North China, the fast wave directions are E-W or NWW-SEE, and the delay times are relatively large, the anisotropy mainly reflects the asthenospheric flow induced by the westward subduction of the Pacific plate; in the northwest, the anisotropy in the Luliang mountain is mainly caused by NW-SE-trending and NNW-SSE-trending lithospheric extension; in the southwest, the anisotropy in the Taihang mountain also reflects the asthenospheric flow around the southeastern corner of the Ordos block. In the northeastern margin of the Ordos block, there exists a small area around the centre of N41 and E113, where the fast wave directions rotate clockwise quickly and the delay times are small, the anisotropy may be related to the mantle upwelling beneath the Datong volcano group. The mid-south CAOB located in the northeast part of the study area, where the E-W trending fast wave directions are consistent with the tectonic strike of fault, collision boundary and absolute plate movement, its anisotropy is not only affected by the lithospheric deformation parallel to the tectonic strike, but also affected by the asthenospheric flow caused by the westward subduction of the Pacific plate.
