Decoherence　of　two　initially　entangled　macroscopic　fields　each　interacting　with　a　loss　environment　is　investigated;　environment　only　have　an　effect　on　the　leakage　of　field＇s　photons.　The　cavity-cavity　entanglement　is　characterized　by　concurrence.　The　results　obtained　by　resolvable　values　show　a　surprising　result:　the　two　entangled　macroscopic　fields　become　completely　disentangled　even　though　the　leakage　rate　of　the　cavities　fields　is　very　tiny.　Then　we　find　that　when　the　cavity　entanglement　disappears,　the　environment　entanglement　appears.　Finally,　we　present　an　explanatory　study　of　other　entanglement　partitions.　©　Chinese　Physical　Society.