A novel copper (II) coordination compound, [Cu(C9H6 O4)(C12H8N2)]. 4H2O (I), (3-carboxyl-5-methyl-salicylaldehyde anion)(phen)copper (II) tetrahydrate, was obtained. The authors present the synthesis method, crystal structure, and the intriguing water chains of (I). The compound is crystallized in triclinic system with space group P–1 and with the cell parameters: a = 6.9507(18) Å, b = 11.025(3) Å, c = 15.142(5) Å, α = 107.617(4)°, β = 95.344(5)°, γ = 103.472(3)°; V = 1058.6(5) Å3, Z = 2, Dc = 1.550 g/cm3, F(000) = 510, μ = 1.083 mm–1, S = 1.030, R = 0.0365, and wR = 0.0951 for 3273 observed reflections [I > 2σ(I)], Mr = 493.95. The coordination geometry around Cu(II) is a slightly distorted square planar with four-coordinated by two oxygen and two N atoms from the ligands. The two types of water rings (tetramembered water rings and hexamembered water rings), which share the same sides, are alternately created and interconnected to form an interesting 1-D water chain like the DNA molecular structure propagating along the a axis. Also, the decamembered water-O intermix clusters formed by crystal water molecules and the O atom of carboxyl of ligands, interconnect with coordination molecules to form 1-D structure along the c-axis and further expand to 2-D network structure in the ac plane. Moreover, the structure is stabilized by the π-π stacking interactions between the adjacent coordination molecules. Supplemental materials are available for this article. Go to the publisher's online edition of Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry to view the supplemental file.