Based on the Hadley sea ice concentration data and NCEP/NCAR reanalysis data,this paper analyzes interdecadal variations of ice-melting amount of sea ice in Arctic region and its interannual relationship with atmospheric variables.Results show that:Arctic sea ice has a significant interdecadal variation and strong regional characteristics.Average and variance of ice-melting amount of East Siberian Sea and Beaufort Sea increase,while average and variance of ice-melting amount in ocean east Greenland decrease.Empirical Orthogonal Function (EOF) analysis is made on ice-melting amount of Arctic sea ice during the three different climate periods (1960-1990,1970-2000 and 1980-2010).The first two EOF modes both have significant interdecadal variations during the three different climate periods.The increase of ice-melting amount of East Siberian Sea is correlated to interdecadal variation of the first EOF mode,while the second EOF mode causes interdecadal melting of sea ice of Beaufort Sea significantly.Furthermore,the corresponding general atmospheric circulation also shows significant interdecadal variations,their interannual relationships with AO/NAO also have interdecadal transition.The second EOF mode of ice-melting amount has a closer interannual relationship with AO,and their correlation coefficient is just 0.186 from 1960 to 1990,but it increases to 0.367 from 1980 to 2010.There is an interdecadal enhancement in the interannual relationship between ice-melting amount of the whole Arctic Ocean and AO,especially in the interannual relationship between ice-melting amount of East Siberia region and AO,and their correlation coefficient is more than 0.4 from 1980 to 2010.The correlation coefficient between ice-melting amount of Beaufort Sea and AO varies greatly,and it reaches up to-0.488 from 1960 to 1990,but it decreases to 0.161 after 1980.However,AO has no significant interdecadal variation.It is Beaufort high that mainly causes the interdecadal variation of interannual relationship between ice-melting amount of sea ice in Arctic region and atmospheric variables.The interdecadal weakening of Beaufort high leads to the decrease of transportation of sea ice from Pole region to East Siberia Sea and Beaufort Sea,resulting in the reduction of sea ice in the two regions,which causes the interdecadal transition of interannual relationship between AO and Arctic sea ice.