Arctic sea ice is undergoing a rapid decline,and the Arctic sea ice volume is an important indicator of global climate change.Sea ice thickness data from two kinds of satellite altimetry data(ICESat and CryoSat-2), together with sea ice concentration data and sea ice age data derived from space borne radiometers,the total and the first-year/multi-year Arctic sea ice volume from 2003to 2013were estimated.Comparison between the ICESat period from 2003to 2008and the CryoSat-2period from 2011to 2013,the Arctic sea ice volume had been decreased by 1 426km~3 and 412km~3in autumn(October-November)and winter(February-March),respectively.These changes are mainly caused by significant reduction of the multi-year sea ice volume in these ten years,the ice volume in autumn and winter had been decreased by 2 108km~3 and 3 206km~3,respectively.Therefore,the dramatic depletion of multi-year sea ice is the main factor of causing Arctic sea ice volume loss.