One hexanuclear cobalt cluster [Co₂^IIICo₄^II(L)₄(CH₃COO)₂(MeO)₄]·MeOH (1) was synthesized by the reaction of H₂L (H₂L = 2-((2-hydroxy-4-methoxy-benzylideneamino)methyl)phenol) and Co(OAc)₂·4H₂O in MeOH under solvothermal conditions. Complex 1 crystalizes in the triclinic space group P with a = 14.397(3), b = 16.625(3), c = 18.992(4) Å, α = 109.47(3)°, β = 99.24(3)°, γ = 112.37(3)°, D_c = 1.464 g/cm³, Z = 2, V = 3741.7(2) ų, the final R = 0.0781 and wR = 0.1436 for 13051 observed reflections with I > 2σ(I). In the structure of 1, two cobalt ions are in 3+ oxidation states and four cobalt ions are in 2+ valence states. The six cobalt atoms are held together by six phenolate oxygen atoms from four L^2– ligands, four oxygen atoms from two chelating acetates and four μ₃-O atoms from four MeO^– groups. The six cobalt atoms are located at six corners of four defective cubanes. Thus, complex 1 displays tetracubane-like topology. Solid-state dc magnetic susceptibilities were measured for 1 in the 2.0～300 K range. Antiferromagnetic interactions were determined for 1.