The eigen values, eigen vector and population analysis of ferrocene and COBALTOCENE show that the first ten molecular orbitals in ferrocene and first seven in COBALTOCENE have contribution from 2pz orbitals of carbon of C5H5-and 3d orbitals of iron or cobalt. The extent of involvement of metal orbitals in the two cases are different. In ferrocene the maximum involvement out of 4s and 4p orbital is in the order 4pz > 4py> 4s> 4px and out of 3d orbitals the order of involvement is 3dyz > 3dxz > 3dz2 > 3dx2- y2 > 3dxy. The involvement of corresponding orbital in COBALTOCENE in respect of 4s and 4p orbitals is in the order 4s> 4pz> 4px and in 3d orbitals the order is 3dyz> 3dxy> 3dxz> 3dz2 > 3dx2-y2. The total involvement in respect of bonding between C5H5-and the metal orbitals as derived from coefficient values is 13.8 in ferrocene and 9.1 in COBALTOCENE. Comparison of eigen values indicate that ten most stable molecular orbitals have their energies in the range-0.4898 to-0.2314 eV in ferrocene and the seven most stable molecular orbitals in the range-0.4935 to-0.3583 eV in COBALTOCENE. The energies of first molecular orbital in ferrocene is-1.1084 eV and in COBALTOCENE-1.1027 eV. The population analysis shows that electrons from 2pz orbitals of carbon and 3d orbitals are provided in molecular orbital in both ferrocene and COBALTOCENE. The magnitude of contribution in the two cases differs significantly as the sum of the coefficient values of three 4p orbitals and five 3d orbitals in the ferrocene and COBALTOCENE are 13.8 and 9.1 respectively.