The　grafting　reaction　of　Cp2Fe　with　Bronsted　acid　sites　in　HY　zeolite　supercages　was　studied　under　high　vacuum　condition.　The　chemical　composition,　structure　and　property　of　the　grafted　sample　were　characterized　by　in　situ　FTIR,　ICP,　XRD,　TPD-MS　and　UV-Vis　DRS.　The　results　showed　that　Cp2Fe　was　adsorbed　strongly　in　the　supercages　of　zeolite　at　the　temperature　lower　than　423　K,　and　was　oxidized　there　into　Cp2Fe+　cation.　When　HY　containing　Cp2Fe　was　heated　at　423　K　for　3　h,　the　cation　reacted　with　the　acidic　hydroxyl　of　zeolite　to　translate　into　a　＂half　sandwich＂　cyclopentadiene　iron　species　CpHFe(OZ　equivalent　to)(3)　(Z:　Si　or　Al　within　the　framework　of　zeolite)　bonding　on　surface　of　the　zeolite　supercages　by　eliminating　a　Cp　group.　Three　CpHFe　groups　could　be　grafted　into　a　supercage,　and　existed　stably　in　vacuum　or　helium　atmosphere　up　to　a　temperature　of　473　K.　The　grafting　reaction　did　not　destroy　the　framework　of　HY　zeolite　but　made　the　BET　surface　area　and　microporous　volume　of　the　raw　HY　decreased.