The hybridization of conduction band is studied for close-packed compounds by means of LMTO method. We emphasize that the heterogeneous coordination would be a necessary condition for intensifying hybridization. In view of the hitherto basic understanding on electron-phonon coupling, a scheme of relation can be outlined as follows: high Tc => high η => significant hybridization=> significant heterogeneous coordination Various experimental results on A15, Bl and other close-packed compouds are in fair agreement with this basic principle.