Qinling-Daba orogenic belt is located between North China craton and the Yangtze craton in an EW narrow zone. As an important part of the central orogenic belt, it is a unique complex typical continental orogenic belt. Studying its crust structure plays an important role for understanding and discussing the interaction among Mainland China blocks. From March 2013 to November 2014, one seismic profile was deployed crossing the North China craton, Qinling-Daba orogenic belt, and the Yangtze craton, which covered about 900 km from Yanchuan to Fulin and included 70 mobile stations. 5638 teleseismic P wave receiver functions were extracted from the waveforms. H-kappa auto-searching stacking and CCP stacking methods were used to study the crust structure beneath the Qinling orogenic belt and the adjacent north and south zones. Crustal thickness along the profile was obtained by H-kappa and CCP stacking methods. The average crust velocity ratio VP/V-S(kappa) beneath each station along the profile was gained by using receiver function H-kappa stacking method and then the Poisson's ratio was calculated. The Poisson's ratio has obvious regional distribution characteristic. Through the CCP stacking methods, the tectonic zone along the profile may be recognized and analyzed. The results indicated, (1) About the crustal thickness: Crustal thickness along Daba mountain is the thickest, which is around 47 similar to 51 km. While going to the Qinling the thickness becomes thinner, which is around 37 similar to 46 km. The Weihe basin reaches the thinnest (around 35 km) at 34 degrees N. On the north side of profile, i.e., the south Erdos. basin, the crust thickness fluctuates slowly, mostly about 44 km. The thickness of the Sichuan basin northeast margin becomes thinner slowly heading south, mostly about 42 similar to 48 km. (2) About the Poisson's ratio: The Poisson's ratio of Qinling orogenic belt is significantly lower than that of southern and northern area. Qinling's Poisson's ratio is less than 0.26, which means that its main crust components are acidic rocks, and its felsic upper crust is thicker than its mafic lower crust. There isn't high Poisson's ratio in Qinling orogenic belt, this shows that there is no extensive partial fusion. (3) About tectonic zone: The boundary between Qinling-Daba orogenic belt and the Yangtze craton is not in the Mianlue structure zone, it should migrate southward to the northeast margin of the Sichuan Basin. North China craton and Yangtze craton is located in the north and south side of Qinling-Daba orogenic belt. They subducted respectively southward and northward with steep and moderate dip along the Qinling-Daba orogenic belt, which made Qinling-Daba orogenic belt an extending outward uplift asymmetric geometry sector model. There is an interface near 33 degrees N between Qinling and Daba Mountain, their regional crustal thickness and Poisson's ratio have different characteristics.
