Based on the NCEP/NCAR reanalysis data, the ERA5 vertical integrated water vapor flux data and the NOAA monthly mean sea surface temperature (SST) data, the interdecadal variations of the relationship between the central and eastern tropical Pacific SSTs and the East Asian water vapor transport (WVT) in December and February during 1950–2019 are investigated. The results indicate that the correlation between the East Asian meridional WVT and the central and eastern tropical Pacific SSTs in December was weak before the mid-1980s and significantly positive after the mid-1980s. The correlation in February was significantly positive during 1950–70 and 1990–2010. The interdecadal variations of the relationship between the East Asian meridional WVT and the central and eastern tropical Pacific SSTs in December are partly due to the fact that the East Asian meridional WVT was mainly modulated by the Pacific–East Asian (PEA) teleconnection during 1986–2019. The circumglobal teleconnection in the Northern Hemisphere, which would induce an anomalous southerly WVT over East Asia corresponding to warm SST anomalies in the central and eastern tropical Pacific, is another mechanism to influence the interdecadal variations of the relationship between the two in December during 1986–2019. The above mechanism enhanced the effect of the PEA teleconnection. The interdecadal variations of the relationship between the two in February are due to the fact that the connection between PEA teleconnection and the East Asian meridional WVT was enhanced during 1950–70 and 1990–2010. Whereas, the East Asian WVT was modulated by the circumglobal teleconnection in the Northern Hemisphere in February during 1971–89,corresponding to the cold SST anomalies in the central and eastern tropical Pacific, which is another mechanism causing the relationship between the two to be insignificant during 1971–89. The above mechanism opposed the effect of the PEA teleconnection.