  Recently, the notion that the number of vacua is enormous has received
increased attentions, which may be regarded as a possible anthropical
explanation to incredible small cosmological constant. Further, a dynamical
mechanisms to implement this possibility is required. We show in an operable
model of cyclic universe that the universe can experience many cycles with
different vacua, which is a generic behavior independent of the details of the
model. This might provide a distinct dynamical approach to an anthropically
favorable vacuum.
