Abstract: In the present paper,we extended these studies of the surface composition of Y,USY,and ZSM-5 zeolites using XPSmethod.The results show that the surface composition (Al/Si) of Y,USY,and ZSM-5 zeolites depend on both that of the bulk and the framwork aluminum strongly or weakly linked in the lattice.The surface layers of Yand Ni-containing Yzeolites are partially deficient in Al.The surface layers of USYand ZSM-5 zeolites are more rich in that element.Again,heating of the NiHYat 300-600℃without the Al removed,gave the results indicating that the surface deficient in Al may be more obvious.