A new dinuclear Tb(III) 4-cyanobenzoate complex [Tb2(4-cba)6(phen)2] (4-Hcba = 4-cyanobenzoic acid and phen = 1,10-phenanthroline) 1 has been synthesized by solvothermal reac- tion in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data: C72H40N10O12Tb2, Mr = 1554.98, triclinic P1, a = 9.903(3), b = 11.769(8), c = 15.078(8) A, α = 111.42(12), β = 96.37(19), γ = 101.24(14)°, V = 1572(1) A3, Z = 1, Dc = 1.642 g/cm3, F(000) = 768 μ = 2.305 mm–1, the final R = 0.0205 and wR = 0.0543 for 5479 reflections with I > 2σ(I). Structural analysis shows that 1 displays an isolated dinuclear structure. Two eight-coordinated Tb(III) ions are bridged by four 4-cba ligands in the syn-syn bidentate coordination mode, and two other 4-cba ligands chelate these two Tb(III) ions. The title complex molecules are connected through π-π stacking interactions to generate a one-dimensional supra- molecular chain. The characteristic infrared spectra, luminescent properties and thermogravimetric analyses have also been discussed.