An effective operator Hamiltonian has been developed for evaluating the excited states of uranyl ion in compounds. Including free-ion and crystal-field interactions, the parametrized Hamiltonian is able to reproduce the energy level structure in good agreement with experimental measurements on uranyl in chloride compounds and nitride complexes. It is shown that the low-lying excited states belong to a nonbonding of configuration (therefore, one Slater integral of G(3) is sufficient to account for the Coulomb electron exchange interaction) and that the spin orbit coupling surpasses the electrostatic interactions in energy level splitting. In comparison with previously reported ab initio calculations, the present studies find that the Coulomb interactions in uranyl were excessively evaluated in the first-principle calculations.