  A master equation for the evolution of two-dimensional universe is derived
based on the simplicial quantum gravity regarding the evolution as the Markov
process of a space-time lattice. Three typical phases, expanding, elongating
and collapsing phase, which have been found in the numerical simulation, are
studied together with their boundaries, analytically. Asymptotic solutions of
the evolution equation for statistical quantities, such as averaged area,
boundary length, and correlation of fluctuations, are obtained for each phase
and boundary.After introducing a physical time the cosmological significance of
each phase is discussed.
