In this paper we have analyzed the unusual rainstorm process in Ningxia Province on June 8, 2002 by using of the synoptic and diagnostic analytical methods. The results show that the rainstorm weather was generated under the favorable “high east and low west” rainfall situation. The main triggering weather system is the 500 hPa cold trough, 700 hPa plateau low vortex and ground occluded front. From the analytical view of dynamics the linear and nonlinear distribution of wind speed contour line on the vertical direction of the Ningxia region stimulated and generated meso-scale gravity inertia wave and vortex-Rossby wave. These two kinds of meso-scale disturbance could possibly become unstable in the shear base flow and finally caused the formation of rainstorm weather process on June 8. Thereby, the persistence of the stable "east blocking situation" and the southwest low jet is the main possible cause of the outburst and continuation of the rainstorm.