Six novel decanuclear clusters with formula of {[Fe 8 Ln 2 (O) 4 (OH) 4 (EtO) 2 (dhbp) 4 (dhbpH) 2 (piv) 6 ]·4EtOH} (Ln = Y (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), dhbpH 2 = 6,6′-dihydroxyl-2,2′-bipyridine, Hpiv = pivalic acid, EtOH = ethanol) have been synthesized and characterized. Single-crystal and powder Xray diffraction analyses reveal that complexes 1-6 are isostructural and show a sandwich-like Fe III 8 Ln III 2 structure, in which the [Ln 2 ] unit is sandwiched by two planar [Fe 4 ] units. Magnetic properties of complexes 1-6 have been investigated and display dominant antiferromagnetic interactions, thereinto, complexes 4 and 6 display weak ferromagnetic behaviors associated with Ln III ions, while others are antiferromagnetic-like features. Furthermore, complex 4 (Fe III 8 Dy III 2 ) shows temperature/frequency-dependent ac signals with an energy barrier of 4.1 K, indicating that complex 4 should be a single-molecule magnet (SMM)