Lhasa River, situated in Qinghai-Tibet Plateau, is the largest tributary of the Yarlung Zangbo River. This region has experienced high warming rates in recent decades, which could have an effect on vegetation growth dynamics. Here, we used dendroclimatological techniques to sample and dispose tree cores of Sabina tibetica in Lhasa River area of Tibet and built standard ring-width index chronology. We assessed the dynamics of tree growth of Sabina tibetica over the past decades, and conducted correlations, partial correlations and moving correlation analysis to analyze the relationship between tree ring-width index chronology and climatic factors. Our results indicated that ring-width index (RWI) had strong positive correlations with total precipitation, relative humidity and Palmer Drought Severity Index (PDSI) from June to October of the previous year and from March to July during the current year's growing season, but significant negative associations with mean temperature and mean maximum temperature from June to September of the previous year and from March to August in the current year, and mean minimum temperature from May to July in the current year. Furthermore, drought because of climate warming had primary influence on tree growth decline in recent decades. If climate warming continues in Lhasa River area, further tree growth decline and increases in tree mortality may occur, potentially driving regional forest loss.