Abstract: Mountain snow is one of the main water source for the Aksu River in Xinjiang. A comprehensive analysis of spatio-temporal variations in the mountain snow in the Aksu River basin can provide a basic support for runoff analysis. In this paper, the snow products of Moderate Resolution Imaging Spectroradiometer (MODIS) during the period of 2001-2014 were used to analyze the snow cover area and its spatio-temporal variations in the Aksu River basin. Results show that in this period of 14 years, the snow cover area took a decreasing trend in the annual, seasonal and monthly scales, with particularly significant decreasing in the annual maximum snow cover and the snow cover in summer. The major significant changes of snow cover occurred in Tuoshigan River mountainou area, mountainous border region and the west of Kumalake River mountain area in the winter and summer, and significant reduction in permanent snow area occurred in the east of Kumalake River mountain area. Without considering other meteorological factors, temperature rising could be a major cause for reduction in the snow cover.