  We present a "feedback compression" model to describe the galactic spheroid
formation and its relation with the central nuclear activity. We suggest that
the star formation itself can serve as the "positive feedback" in some
extremely dense region to trigger the starburst. The star formation rate as
well as the related stellar feedback-induced turbulence will be maximized under
the regulation of the background dark halo's gravity. There is also stellar
feedback acting inward to confine and obscure the central black hole (BH) till
the BH grows sufficiently large to satisfy a balance condition between the
accretion disk wind and the inward stellar feedback. The extremely vigorous
star formation activity, the BH - bulge relations, the maximum velocity
dispersion as well as the maximum BH mass are investigated based on such
scenario, and are found to be consistent with observations.
