Relation between variation of δ¹⁸O in precipitation in Yarlungzangbo River basin and the moisture flux was analyzed with NCEP/NCAR reanalysis grid data and δ¹⁸O in precipitation at four stations ( Lazi, Nugesha, Yangcun and Nuxia ) of the region investigated. For the spatial variations, there is obviously positive correlation between them for the whole basin. With the decrease of moisture flux from the downstream to the upstream,δ¹⁸O in precipitation becomes lower gradually. However, for the temporal variations, higher δ¹⁸O in precipitation of spring is linked to small moisture flux and low δ¹⁸O in precipitation of summer is linked to large moisture flux. And then, a model involving meteorological data from NCEP/NCAR was established and successfully traced the moisture transport trajectories at Yangcun station. Based on the traced results and δ¹⁸O in precipitation at Yangcun station, the relation between δ¹⁸O in precipitation in Yarlungzangbo River basin and the moisture transport history was discussed. We found that humid marine air mass from the Indian Ocean in general had significantly lower δ¹⁸O values than continental air mass from north or local re-evaporation. The fluctuation of δ¹⁸O in precipitation during monsoon season is very pronounced and the lower values are usually related to far distance and multilayer of moisture transport, as well as moisture crossing the Himalaya Mountain.