Abstract: The stable isotopes characteritics of hydrogen and oxygen in precipitation is an important aspect of the regional isotope hydrologic cycle. The variations of δD and δ¹⁸O values in event-based precipitation samples are analyzed. The samples were collected from three stations (No.1, Zongkong, Houxia) in the upper Urumqi River basin from May 2006 to August 2007. The δ¹⁸O in event-based precipitation exhibits an extremely wide range and a distinct seasonal variation with enriched values in summer and depleted values in winter. The slopes and intercepts of the local meteoric water lines (LMWLs) along the Urumqi River Basin are No.1>Zongkong>Houxia>Urumqi the nearest Global Network of Isotopes in Precipitation (GNIP) station. The δ¹⁸O and δD values in event-based precipitation and the mean air temperature show a significant positive correlation, and a better linear relation exists between δ¹⁸O and air temperature than that of δD. Seasonal variations can be observed in d-excess of precipitation. The results of air-mass back trajectories of each precipitation event with the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicate a dominant effect of westerly air masses in summer and the integrated influence of westerly and polar air masses in winter for the study area.