Holoceneδ18O records from various archives (ice cores, cave stalagmites, and peat sediments) from the Xinjiang region of northwestern China, in arid central Asia (ACA), are all derived ultimately from local precipitationδ18O (δ18Op). Neverthe-less, they have been proposed as indicators of different climatic parameters, such as wetness and temperature changes. This article summarizes previously reported records of moisture sources for the Xinjiang region and the results of modern observations conducted at an ice core site and a peat site in the Altai Mountains. The findings are used to propose that the overall positive trends in Holoceneδ18O records from the various archives from the Xinjiang region primarily reflect the Holocene's long-term warming trend. It is concluded that more site-specific modern observations are needed to further elu-cidate the environmental significance of Holoceneδ18O records from this region, especially for the separation of different seasonal temperature signals present withinδ18O records.