A two-level primitive equation spectral model is developedfor investigating the dynamic effects of the Qinghai-Xizang Plateau onthe atmospheric low-frequency oscillations in the summer flow pattern.Conclusions are drawn as follows:(1)Topography can stimulate low-fre-quency oscillations, which have obvious geographical characteristics.(2)Low-frequency oscillations assume a barotropic structure on thenorthern side of the mountains and a baroclinic structure on the southern side. (3)Wave propagation shows characteristics of quasi-stationary Rossby waves.