Two metal–organic frameworks [Mn 4 (bptc) 2 (bpy) 2 ] n (1) (H 4 bptc=biphenyl-2,3,3′,5′-tetra-carboxylic acid, bpy=2, 2′-dipyridine) with Mn 4 clusters and {[Mn 2 (bptc) 2 (H 2 O) 8 ]⋅4H 2 O}(2) were obtained through hydrothermal reaction. X-ray diffraction analysis shows that both complexes 1 and 2 crystallize in the Triclinic system, space group of P-1. The Mn(II) ions have two kinds of coordination mode in complex 1, one is five- coordinated and the other is six-coordinated. Mn(2) ion is bridged to neighboring Mn(2)A(A:1−x, 1−y, 2−z) by two μ 2 -O carboxyl atoms to afford a {Mn} 4 cluster together with another two symmetrical Mn(1) and Mn(1)a. The {Mn} 4 clusters are further connected through the bptc 4− ligands each other, giving rise to a 2D network. There is a Mn 2 O 2 parallelogram-core in every {Mn} 4 cluster, and to the best of our knowledge this is the first time observed. Complex 2 consists of the dinuclear manganese (II) unit, which is further linked by hydrogen bonds to form a 3D framework structure. Magnetic measurements show there is a weak anti-ferromagnetic interaction in complex 1. Moreover, the IR, element analysis, and thermal stability of the two complexes have been investigated systemically.