Based on the massive teleseismic waveforms collected by the China Array II project, we investigate the 410 km and 660 km discontinuities (referred to as ‘410’ and ‘660’) beneath the northeastern Tibetan Plateau. After all of the 95747 radial receiver functions are stacked into each 0.5x0.5° grid, the P410s and P660s arrival times are Picked. Referring to the local 3-D tomographic model, the ‘410’ and ‘660’ depths are 416±0.6 km and 676±0.8 km, respectively, and the mantle transition zone (MTZ) thickness is ~260 km. Considering the remote effect of the subducted Indian Plate and Pacific Plate, we focused on the depressed two discontinuities. In particular, along the northeastern boundary of the Tibetan Plateau, the ‘410’ is confirmed as a dynamic barrier to hot asthenospheric flow, which escapes from the Tibetan Plateau and is obstructed by the rigid cratonic lithosphere in its surrounding area. The ‘660’ is obviously affected by cold anomalies that are delaminated or removed from the thickened lithosphere. In the western NCC(North China Craton), combining with the depressed ‘660’ and relatively larger P660s-P amplitude ratio, we speculate that a certain amount of water has accumulated in the lower MTZ, while the low Vs velocity around the 660 km depth may be related to melting. According to previous results, we propose a mantle convection model driven by the edge-derived convection of the subducted Pacific Plate. The cratonic lithosphere beneath the Ordos block may also undergo slow modification.