In ethanol, a mononuclear cobalt(Ⅲ) complex incorporating 2′-(2-Thienylidene)-2-Hydroxybenzoylhydra- zide has been synthesized and characterized by IR, UV-Vis, elemental analysis and X-ray crystal structure analysis. The crystal belongs to triclinic system, space group P1 with cell constant, a=1.230 69(10) nm, b=1.329 18(11) nm, c=1.330 56(11) nm, α=113.702(2)°, β=91.590(2)°, γ=100.846(2)°, V=1.944 4(3) nm3, Z=2, μ=0.662 mm-1, Dc=1.482 g·cm-3, F(000)=896, Rint=0.048 7. The crystal structure shows an anionic didentate ligand O and N donors in this work. The cobalt(Ⅲ) atom is hexacoordinated with oxygen atom from keto group and nitrogen atom from amide to form a cobalt atom for the core octahedral structure. CCDC: 748882.