Vegetation phenology is the most objective and sensitive indicator of environmental conditions and climate change.Therefore,grassland phenology research in Xinjiang has significance for understanding and predicting the dynamics of terrestrial ecosystems in this area.In this study,the spatio-temporal changes in grassland phenology in Xinjiang were evaluated using phenology data from the land cover dynamic product (MCD12Q2)for Xinjiang during 2001-2014.The main conclusions were as follows:1)The perennial mean vegetation phenology in Xinjiang grassland showed obvious regional differences from low to high altitude.With every 1000mincrease in elevation,the SOG(start of the growing season)was delayed by 13d,the EOG(end of the growing season)was advanced by 7d,and the LOG(length of the growing season)was shortened by 20 d.2)SOG occurred within 100th-136th days,EOG occurred within 256th-291th days,and the LOG occurred within 122-190days.3)Grassland SOG was advanced by 0.11d·yr~(-1),while the EOG was delayed by 0.14d·yr~(-1),and the LOG was prolonged by 0.25d·yr~(-1).