A new complex with the formula [Na(H 2 O) 2 ] 6 [MoCo 6 O 12 (H 2 O) 12 ] · 4.3H 2 O has been synthesized and characterized by single crystal X‐ray diffraction, thermal study, infrared spectrum. The complex is rose rhombic crystal and space group R‐3 m with a=11.9396(15) Å, b=11.9396(15) Å, c=22.995(3) Å, α=90°, β=90°, γ=120°, V=2838.9(9) Å 3 , Z=3, and R 1 =0.0612. The structure of the anion [MoCo 6 O 12 (H 2 O) 12 ] 6- has a hexagonal plane structure composed of a central Mo ion surrounded by six octahedron CoO 6 groups. Each CoO 6 shares an edge with each of its two neighboring CoO 6 and another edge with the MoO 6 octahedron. This is similar to the Anderson‐type strucure. This new complex is colbaltmolybdate described. [ABSTRACT FROM AUTHOR]