The NCEP/NCAR reanalysis data are employed to analyze the diurnal variation of the diabatic heating and atmospheric circulation over the Tibetan Plateau and it's surrounding areas. The atmosphere over the TP is most sensitive to the diurnal change of heating, and it results in the vivid diurnal change feature over the TP and its surrounding areas. Its diurnal change is consistent with that of the heating field's, especially with diurnal change of the solar heating. Because the mass of the atmospheric column over the TP is much lighter than other regions, the diurnal change of solar radiation heating causes more significant circulation variation over the TP. The equation of the potential vorticity is employed to diagnose the dynamics of diurnal circulation variation in the paper. The result shows while the solar radiation gradually enhanced in the daytime, the positive vorticity of lower level atmosphere and negative vorticity of high level atmosphere over the TP is increase. All these lead to the most significant circulation and weather diurnal changes over the TP and its surrounding areas. The features of the diurnal change of the atmospheric circulation are in accordance with both theory and data analysis results in their phase and circulation patterns.