Liupan Mountain—Ordos Basin Deep seismic sounding profiles in the northeastern margin of Qinghai—Xizang (Tibet) plateau along the Near East — West direction laid about 420km, which goes across the Ordos basin, Liupan Mountain orgenic belt and Qin Qi plots. According to travel time data of 6 seismic phases and the amplitude information which were recognized by the recorded sections in 6 shots of the explosion , the authors obtained the two dimensional P waves velocity structure along the profile, the average crustal velocity is 6.38～6.40km/s and the crustal depth is 41.7~48.2km in Ordos basin. In Liupan Mountain area, the average crustal velocity is 6.40 ~ 6.42 km / s, crustal thickness of up to 53~54km. In Qin Qi fold zone, the average crustal velocity minimum is 6.32~6.40km/s, crustal thickness is 50.3~53km. The Moho boundary is shallow in eastern and deep in western, obviously westward tilt. The most shallow Moho depth is 417km in Ordos Basin east. Below Liupan Mountain, the deepest depth of the Moho is 54km. The Head wave(Pn) of Moho boundary appears after the 220km, the velocity is 7.8～8.1km/s. To discuss the relation of basin—mountain structure finally.