In this paper, the electronic structures of the complex ions (CrO6) in three different valence states of chromium ion (Cr2+, Cr3+, Cr4+) are calculated with the spin-polarized MS-Xaaaa method. The one-electron eignvalues and eignfunctions, the energy levels, and the optical transitions under the D4k symetry are given. The calculated results are discussed comprehensively.