Novel alkoxo-bridged lanthanide(III) dinuclear complexes Na-4[Ln(2)(mu-dpta-O)(2)] (Ln = Gd-III, Ho-III, and Yb-III; H(4)dpta-OH = 1, 3-diamino-2-hydroxypropane-N, N, N', N-tetraacetic acid) were prepared and characterized. X-ray analysis for the Yb(III) complex indicated that each Yb atoms, which is surrounded by four terminal O atoms from carboxylate, two bridged O atoms from alkoxo, and two N atoms in two different dpta-O ligands, is situated in an eight coordinate geometry.