The formula of gas pressure inside HGM (hollow glass microspher es) wit h thin wall during procedures of gas filling at one step or steps and those of gas leak rate and gas retention halflife of HGM were derived.The confinement conditions to avoid HG M failure in the procedure of gas fill at steps were developed. Then the permeabi lity of D2 through HGM was experimentally measured,and the results were in good agreement with the calculated ones.