A Trihydrated complex of benzimidazole copper(Ⅱ) sulfate [(C7H6N2)4CuSO4]·3H2O was synthesized and structurally characterized. The crystal structure of this compound is built up of six solvated water molecules and two dissimilar copper ions identified as Cu1 and Cu2. The coordination geometry of copper(Ⅱ) is a slightly distorted square pyramid. The four equivalent tertiary nitrogen atoms of the benzimidazole ligand form an equatorial plane, while the oxygen atoms of sulfato occupy the axial site. In the solid state, the title compound forms a three dimensional network structure via hydrogen bonds. The benzimidazole, sulfato ion and H2O moieties are connected by the intermolecular hydrogen bonds. The (EPR) spectrum shows axial symmetry with g⊥=2.039 and g∥=2.285. Variable temperature magnetic susceptibility shows that there is a weak antiferromagnetic interaction between the neighboring copper(Ⅱ) ions.