Abstract: It is important to study water resources vulnerability in order to identify water resource problems and regulate water security. Water resources of the Yarlung Zangbo River basin are abundant, but its distribution is uneven, frequently flood and drought disasters and lower social economic development trigger spatial temporal differences of water resources vulnerability. Based on the monthly meteorological data from 1965 to 2014, the precipitation distribution and the dry-wet partition are analyzed. We analyzed the temporal spatial distribution of flood and drought disasters with the standardized precipitation index, and subsequently applied the entropy method to examine the temporalspatial differences of water resources vulnerability, based on the following three parameters of ‘flood and drought disasters and desertification’, ‘water supply and benefit’, and ‘regulatory capacity’. The results indicate that: 1) annual average precipitation is 458 mm in the basin and increases from northwest to southeast. Most of Rikaze in the upstream region, as well as Lasa and Shannan in midstream region are located in the semiarid climate zone, while Linzhi in the downstream belongs to the humid climate zone; 2) Spring droughts and midsummer floods usually occur within the basin, and the frequency of floods is lower than that of droughts. Lasa and Linzhi are more prone to experience severe droughts, while Shannan is more vulnerable to floods; 3) Water resources vulnerability in the basin and the four cities/prefectures shows a downward trend from 2005 to 2014, but the reduction in vulnerability is faster in Shannan and Linzhi than in Lasa and Rikaze; 4) The dominant factors influencing water resources vulnerability are floods, droughts, water use efficiency, management capacity, and GDP. In short, water resource vulnerability in this basin is dominated by floods and droughts, weak regulatory capacity and inefficient use of water.