Abstract: A simplified MO treatment has been proposed for the cluster compounds containing both bridging and terminal ligands. The terminal ligands of a considered cluster can be treated as fragment, if only the electronic structures of the skeleton are interested in We chose a pars of the fragment MO's in the terminal ligands which are calculated beforhand as the valence orbitals of these fragments and retain a common set of skeleton atoms which is treated as in standard CNDO. The largest advantage of this approximation is in the reduction of the number of electrons and basis functions, and hance the reduction of computer time. The detailed description of the formalism has been presented and the procedure of the calculation has been programed and performed on a PDP-11-70 computer.