雅鲁藏布大峡谷地区（以下简称大峡谷地区）是青藏高原重要的水汽输送通道，大峡谷的水汽输送对高原天气气候等有着重要影响。本文基于1986-2021年ERA5再分析资料和CN05. 1日降水资料，分析了高原夏季风期和冬季风期大峡谷的水汽输送特征，并研究了其与江河源区降水在夏季风期的关系。结果表明：（1）大峡谷地区可降水量在空间上整体呈东南多、西北少的分布，在时间上呈增长趋势，夏季风期增长幅度大于年平均和冬季风期。大峡谷水汽通量主要来自印度洋至孟加拉湾的西南水汽输送，其次是中纬度南支西风水汽输送。（2）大峡谷南、西边界在全年都是水汽输入边界，东、北边界是水汽输出边界，夏季风期水汽输送通量强于冬季风期。大峡谷是净水汽通量正值区，净水汽收入呈显著减少趋势。（3）低层1000~600 hPa，源于印度洋至孟加拉湾和西太平洋上的水汽输送从大峡谷南边界进入高原，南边界是水汽输入的主要边界；高层600~300 hPa，中高纬度地区是显著的西风水汽输送，水汽主要从西边界输入，东边界输出。（4）夏季风期大峡谷的水汽通量与江河源中东部地区的降水存在显著正相关关系。孟加拉湾异常的东南水汽输送和孟加拉湾北部及高原西南侧异常的西南水汽输送从大峡谷西和南边界进入，为江河源中东部带来充足水汽，水汽在江河源中东部上升导致降水偏多。

The Yarlung Zangbo Grand Canyon region（YZGC）is an important water vapor transport channel on the Qinghai-Xizang Plateau，and the water vapor transport of the YZGC has an important impact on the weather and climate of the plateau. Based on the ERA5 reanalysis data and CN05. 1 precipitation data from 1986-2021， this paper analyzes the water vapor transport characteristics of the YZGC during the summer monsoon and winter monsoon periods and studies its relationship with precipitation in Three-River Source Region（TRSR）during the plateau summer monsoon period. The results showed that：（1）The precipitation in the YZGC was more in the southeast and less in the northwest and showed an increasing trend in time，and the increase in the summer monsoon period was greater than that of the annual average and the winter monsoon period. The water vapor flux of the YZGC mainly comes from the southwest water vapor transport from the Indian Ocean to the Bay of Bengal， followed by the westerly water vapor transport from the southern branch of the mid-latitudes.（2）The south and west boundaries of the YZGC are the water vapor input boundaries throughout the year，and the east and north boundaries are the water vapor output boundaries，and the water vapor transport flux during the summer monsoon is stronger than that during the winter monsoon period. The YZGC is a positive area of net water vapor flux，and the net water vapor income shows a significant decreasing trend.（3）The low-level 1000~600 hPa originates from the Indian Ocean to the Bay of Bengal and the western Pacific Ocean，and the water vapor transport enters the plateau from the southern boundary of the YZGC，and the southern boundary is the main boundary of water vapor input. The upper layer is 600~300 hPa，and the middle and high latitudes are significant westerly water vapor transport，and the water vapor is mainly imported from the western boundary and exported from the eastern boundary.（4）There is a significant positive correlation between the water vapor flux of the YZGC and the precipitation in the central and eastern parts of the TRSR during the summer monsoon. Anomalous southeast water vapor transport from the Bay of Bengal，as well as anomalous southwest water vapor transport from the northern Bay of Bengal and the southwestern side of the plateau，enters through the western and southern boundaries of the YZGC，providing ample moisture to the central and eastern parts of the TRSR. The upward motion of this water vapor in the central and eastern TRSR leads to increased precipitation.