The mono-nuclear complex [Cdq3][Cd(qH)3](ClO4)CH3OH has been synthesized by 8-quinolinol and hydrated cadmium perchlorate in methanol solution. The crystal belongs to triclinic, space group P1 with a = 11.1449(15), b = 13.3334(18), c = 17.654(2) ?, α = 85.555(2), β = 88.497(2), γ = 75.681(2)°, V = 2534.1(6) ?3, Z = 1, C110H86Cd4Cl2 N12O22, Mr = 2448.41, Dc = 1.604 g/cm3, F(000) = 1232 and μ = 0.961 mm-1. The structure was refined to R = 0.0387 and wR = 0.0973 for 7775 observed reflections (I > 2σ(I)). In this crystal there exist two independent mono- nuclear complexes of [Cdq3]- and [Cd(qH)3]2+. Each cell contains two [Cdq3]- anions, two [Cd- (qH)3]2+ cations, two ClO4- anions and two methanol molecules.