A unique three-dimensional (3D) supramolecular compound, [Co(dpe)(BTC)(H 2 O)][Co(dpe)(BTC)(H 2 O) 3 ]-[Co(dpe)(HBTC)(H 2 O)][Co(dpe) 2 (H 2 O) 3.5 (EtOH) 0.5 ]•1.5H 2 O (1; dpe = 1,2-bis(4-pyridyl)ethane and H 3 BTC = benzenetricarboxylic acid), has been synthesized and structurally characterized by the single-crystal X-ray diffraction method. Compound 1 consists of four coordination polymers (CPs), two are two-dimensional (2D) layered metal−organic frameworks (MOFs) with (4,4) topology of [Co(dpe)(BTC)(H 2 O)] − and [Co(dpe)(HBTC)(H 2 O)], whereas the other two are onedimensional (1D) polymeric chains of [Co(dpe)(BTC)(H 2 O) 3 ] − and [Co(dpe)(H 2 O) 3.5 (EtOH) 0.5 ] 2+ . The 3D supramolecular architecture of 1 is constructed via the penetration of interdigitated double-layered 2D rectangular-grid frameworks by two 1D coordination polymeric chains and entangled tightly by the subtle combination of intermolecular hydrogen bonding and π−π interactions among the four CPs. Controlled heating of the as-synthesized crystal 1 at ∼160 °C produces a desolvated 1 and accompanying color-changing behavior from pink to deep-blue, and the deep-blue desolvated 1 regenerates the pink rehydrated crystal with the chemical formula of [Co(dpe 2) upon exposure to water vapor. The structural determination of 2 shows almost the same structural characteristics as that of 1 with the only difference being the replacement of disordered coordinated solvent (half H 2 O and half EtOH molecules) by H 2 O and the numbers of solvated water molecules. The cyclic thermogravimetric analysis and powder X-ray diffraction measurements of desolvated 1 demonstrate a reversible rehydration/dehydration property, which is associated with solid-state structural transformation and thermally induced UV−vis absorption properties.