Two　lanthanide-oxo-cluster　polymers　were　synthesized　by　hydrothermal　reaction　using　Ln(2)O(3)　as　initial　lanthanide　materials:　[Ln(4)(SO4)(4)(OH)(4)(H2O)(7)]center　dot　4H(2)O　(Ln　=　Er　1,　Ho　2),　and　characterized　by　PXRD,　IR　spectra,　X-ray　single-crystal　diffraction,　2D　IR　correlation　spectra　and　UV-visible　absorption　spectra.　Single-crystal　X-ray　analyses　reveal　that　compounds　1　and　2　are　isostructural,　and　they　are　both　crystallized　in　the　orthorhombic　system　Pccn　space　group.　Compound　1　is　a　3D　lanthanide　cluster　polymer　based　on　tetranuclear　cubane-like　[Er-4(mu(3)-OH)(4)](8+)　cations　and　SO42-　anions.　The　overall　structure　of　1　can　be　assigned　to　6-connected　pcu-type　topology　with　the　point　symbol　of　(4(12).6(3)).