In the background of warming in recent decades,mountain glaciers in China had also changed dramatically.Glacier changes in the eastern part of Tianshan have obvious indication to glacier changes on the Tianshan Mountains and the China′s western region.The Bogurda,Balikun and Hal Rick mountains were selected as the regions to search a method for delineating glacier extent by Landsat TM,ETM+images of 1990,2001and 2011.The changes of glaciers were analyzed under the support of the geographic information system technology.The results indicate that glacier whole range is larger in eastern Tianshan.The total areas have reduced by 26.80%in the past 21years.However,Bogurda,Balikun,Hal Rick mountains have retreated 33.58%,25.67%,16.08%,respectively.The glaciers mainly distributed in the northwestern slope,northern slope and northeastern slope,but retreat rate of eastern slope was the largest,reaching to 30.68%.Glaciers in the study area mainly distributed at the altitude of 3 600~4 600m,glacier retreat in the 3 300~3 400m was the fastest.The results from the studies show that rising temperatures and fluctuation rainfall are the main causes of glacier retreat in eastern Tianshan.In addition,topographic condition is a key factor for glacier changes as well.