Abstract: The Asian summer monsoon regions are mainly atmospheric composition transport pathways from the troposphere to the stratosphere, and have large contribution to the variation of the stratospheric water vapor. Previous research show that the Tibetan Plateau (TP) and its surround regions contribute most water vapor transport from the troposphere to the stratosphere over Asian summer monsoon regions. The multi-year average Aura Microwave Limb Sounder (MLS) satellite observations, and the ERAi and MERRA reanalysis datasets are used to diagnose the water vapor maintenance and quantify the water vapor transport from the troposphere to the stratosphere over the TP and the Rocky Mountains (RM) in July and August. The three-dimensional structure of isentropic surfaces and the tropopause is favorable for adiabatic water vapor transport from the troposphere to the stratosphere over the TP. According to the quantified result from ERAi, there is a significant zonal adiabatic water vapor transport pathway from the northeast of the South Asian high to the central Pacific at 340-360 K, and the averaged water vapor mass flux is nearly 7×10³ kg s^-1 during July and August. Strong diabatic water vapor transport pathway is found in the southern flank of the TP at 370-380 K, which is controlled by deep convection and large-scale ascending motion, and the averaged flux is about 0.4×10³ kg s^-1 during July and August. Besides, at 350-360 K, there is a weak meridional adiabatic water vapor transport pathway from the Iranian Plateau to western flank of the TP, and a weak zonal adiabatic water vapor transport pathway is also found from the eastern flank of the RM to the western Atlantic, where the water vapor mass flux is about 2.5×10³ kg s^-1.