  Self-gravitating accretion disks collapse to star-forming(SF) regions
extending to the inner edge of the dusty torus in active galactic nuclei
(AGNs). A full set of equations including feedback of star formation is given
to describe the dynamics of the regions. We explore the role of supernovae
explosion (SNexp), acting to excite turbulent viscosity, in the transportation
of angular momentum in the regions within 1pc scale. We find that accretion
disks with typical rates in AGNs can be driven by SNexp in the regions and
metals are produced spontaneously. The present model predicts a
metallicity--luminosity relationship consistent with that observed in AGNs. As
relics of SF regions, a ring (or belt) consisting of old stars remains for
every episode of supermassive black hole activity. We suggest that multiple
stellar rings with random directions interact and form a nuclear star cluster
after episodes driven by star formation.
