Abstract Using mixed ligands and hydrothermal reactions, five new coordination polymers, [Co( o-CCA)(bpe)(H 2O)] n · 0.25 nCH 3OH ( 1), [Ni( o-CCA)(bpe)(H 2O)] n · 0.5 nH 2O ( 2), [M( p-CCA)(bpe) 1.5(H 2O)] n · nH 2O (M = Co, ( 3); Ni, ( 4)) and [Co( o-BDC)(bpe)(H 2O)] n · nH 2O ( 5) (H 2CCA = carboxycinnamic acid; bpe = 1,2-bis(4-pyridyl)ethane; o-H 2BDC = 1,2-benzenedicarboxylic acid) were obtained. Complexes 1– 4 possess complicated 3D metal-organic frameworks, but different position of functional dicarboxylate groups results in different architecture, forming diversity of structures. 1 and 2, 3 and 4 are isomorphous, respectively, in which solvent molecules are clatharated. When o-BDC instead of CCA was used, complex 5 was obtained, which is of (4,4) 2D grid-like layers with cavities. Thermal stabilities of complexes 1– 4 were discussed.