By using the satellite Temperature of Brightness Blackbody (TBB) data, NCEP 1°×1° reanalysis data, and nonhydrostatic mesoscale numerical model MM5, control experiment and six sensitivity experiments which are adiabatic, no surface sensible heating, double surface sensible heating, no evaporation effect, no latent heat of condensation, and no water vapor, are performed for two cases of plateau vortex occurring during 28－29 July 2005 and 29－31 July 2009, and the happening, development, and structure change of the plateau vortex during 28－29 July 2005 are mainly discussed. The results show that the vortex center and the vortex structure at 500 hPa simulated in the control experiment are the same as actuality. The adiabatic conditions affect the formation, development and structure change of the vortex most remarkably. The latent heat of condensation and the water vapor do not play decisive roles in formation of the vortex, but play key roles in vortex maintenance and structure characteristics evolvement. Surface latent heat has some effect on the development of the vortex, and no surface latent heat slightly decreases the strength of the vortex. The effect of surface sensible heat on the vortex is different for different cases, and depends on the developing stage of the vortex, and also that the developing stage is daytime or night.