Monthly averaged ERA-Interim reanalysis datasets and SWOOSH water vapor data are used to analyze the interannually geographic pattern of the water vapor mass anomaly in 340–360K lay-ers and its maintenance over the Tibetan Plateau (TP) region in July–August. Results show that the interannual variations of the geographic patterns of the water vapor mass anomaly are domi-nated by three leading modes, namely the uniform mode, the east-west dipole abnormal mode and the south-north dipole mode. Associated with the positive phase of the uniform mode, namely more (less) water vapor mass over the entire TP area, the stronger convective and upward dia-batic water vapor mass transport over the TP regions leads to an enhanced convergence of water vapor mass, while the strengthened South Asian High (SAH) results in an enhanced divergence and convergence of adiabatic water vapor mass transport over the TP and to the west of TP, and vice versa for the less water vapor mass over the entire TP area. For the positive phase of the east-west diploe mode when the water vapor mass is more/less in the west/east of TP area, both the convective and the diabatic water vapor mass transport are enhanced over the western TP but weakened over the central and eastern TP. Meanwhile, the center of SAH shifts westward giving rise to a stronger westward adiabatic water vapor mass transport from the TP to the Iranian Plat-eau in the upper troposphere. Such diabatic and adiabatic processes cooperatively contribute to the abnormal convergence of water vapor mass over the western TP, but divergence in the central and eastern TP in the upper troposphere. When the water vapor mass is less/more in the west/east of TP area, the results are also opposite. For the positive phase of the south-north dipole mode when water vapor mass is more/less in the northern/ southern TP, the center of SAH shifts north-ward giving rise to a stronger northward adiabatic water vapor mass transport in the northern TP in the upper troposphere and a stronger upward diabatic water vapor mass transport also in lower layers are found, which both leading to the abnormal convergence of water vapor mass. While the divergence of adiabatic water vapor mass transport and the convergence of diabatic water vapor mass transport are weakened in the southern TP, vice versa when water vapor mass is less/more in the northern/ southern TP.