Abstract: The interannual geographic patterns of the upper tropospheric water-vapor-mass anomaly are dominated by a uniform abnormal mode and an east–west dipole abnormal mode over the Tibetan Plateau (TP) regions in July–August. In this paper, we analyze the relationship between these two leading modes and the adiabatic and diabatic water-vapor-mass transport from the troposphere to the stratosphere based on the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis (ERA-Interim) datasets and the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) trajectory model. Results show that when the water vapor mass is dominated by the positive (negative) phase of the uniform abnormal mode, i.e., there is more (less) water vapor mass over the entire TP area, the intensity of the South Asian High (SAH) and the upward diabatic water-vapor-mass transport are enhanced (weakened), which means both the adiabatic and diabatic water-vapor-mass transport from the troposphere to the stratosphere are stronger (weaker). The regions and layers where the adiabatic and diabatic water-vapor-mass transported from the troposphere to the stratosphere change very little from the positive to negative phases of the uniform mode, although the layers in which the diabatic water-vapor-mass transported from the troposphere to the stratosphere are slightly higher for the positive phase. When the water vapor mass is dominated by the positive (negative) phase of the west–east dipole abnormal mode, that is, when there is more (less) water vapor mass in the west (east) of the TP, the SAH center shifts westward, enhancing the adiabatic water-vapor-mass transport from the troposphere to the mid-latitude stratosphere in the northwest and northeast flanks of the TP as well as the meridional adiabatic water-vapor-mass transport from the troposphere to the tropical stratosphere in the upper layers in the south flank of the TP. However, the meridional adiabatic water-vapor-mass transport from the troposphere to the mid-latitude stratosphere in the north flank of the TP is weakened. Meanwhile, the diabatic water-vapor-mass transport from the troposphere to the stratosphere is enhanced over the TP, whereas it is weakened in the upper layers in the south flank of the TP and the lower layers in the north flank of the TP. When the opposite occurs, there is less (more) water vapor mass in the west (east) of the TP. Trajectory model simulation experiments for the positive phase of the uniform abnormal mode confirm that higher frequency trajectories enter the stratosphere adiabatically over the TP regions. Trajectory model simulation experiments for the positive phase of the west–east dipole abnormal mode are in agreement with the analyzed results, which show higher (lower) frequency trajectories entering the stratosphere adiabatically in the northwest, south, and northeast flanks (north flank) of the TP.