  We consider the radiation-hydrodynamical formation of a dusty wall in the
circumnuclear regions of the Circinus Seyfert 2 galaxy. We focus on the
radiative flux force due to the circumnuclear starburst, the nuclear starburst
and the active galactic nucleus (AGN), and analyze the equilibrium
configuration and stability of the dusty gas in the circumnuclear regions. The
mass distributions used to model the gravitational fields are determined by the
observed rotation velocities of the stars and of the gas. Moreover, by using
the simple stellar evolution in the circumnuclear starburst, the bolometric
luminosity of the starburst is estimated as a function of time. As a result, it
is shown that the radiation force by the circumnuclear starburst does play an
important role to build up a radiatively-supported dusty wall of $\la$ 100 pc,
which obscures the circumnuclear regions with $A_V$ of a few magnitudes. It is
also found that the age of a circumnuclear starburst when the circumnuclear
regions are enshrouded by the dusty wall is constrained to be $\la 10^8$ yr,
which is consistent with the age observationally inferred for the starburst, $4
10^7$ yr $-1.5 10^8$ yr.
