This　paper　firstly　describes　the　definitions　of　stock　and　virtual　organization　(VO),　then　gradually　show　the　importance　of　inventory　management　under　the　environment　of　VO.　Although　the　classical　model　of　Economic　Order　Quantity　(EOQ)　is　widely　used　in　the　inventory　management　of　traditional　enterprises,　it＇s　not　applicable　to　VO.　As　an　integrated　system　composed　of　two　or　more　traditional　enterprises,　VO　is　quite　different　from　those　traditional　enterprises.　When　it　comes　to　the　problem　of　VO＇s　inventory　management,　it＇s　necessary　to　take　both　the　interests　of　suppliers　and　demanders　within　the　VO　into　consideration.　Therefore,　this　paper　dwells　on　the　differences　of　EOQ　Model　between　traditional　enterprises　and　VO.　Further,　a　modified　model　is　proposed　based　on　integration　theory　and　system　theory.　Finally,　it　puts　forward　some　inspirations　and　suggestions　accordingly,　in　order　to　maximize　the　interests　of　the　whole　group　and　raise　the　enterprise＇s　economic　efficiency.　©2010　IEEE.