This study deals with complexity, frequency spectrum and velocity model of the crust mantle transitional zone in different tectonic units along the northeast margin of Qinghai Xizang plateau, based on P M P waveform data from two deep seismic sounding profiles passing through the area.

Stresses in cone cylinder shells with toroidal transition inserted are investigated by an analytical method, and buckling pressures for the shells are presented by Rayleigh Ritzs method.

The solid-shell transient elements established before will cause an unrealistic high level of stress because of using a wrong expression for the initial thermal strain and restricting the Poisson s effect for the material in the element.

The solid-shell transient elements established before will cause a unrealistic high level of stresswhen being used in thermal stress analysis.

These data,combined with the published seismic velocities for the area,are used to define the composition and structure of the crust-mantle transitional zone beneath southwestern Tianshan.