  The time development of a model of (2+1)-dimensional torus universe is
studied based on background field equations which follow from a string theory.
The metrics in various cases are characterized by a real parameter which
specifies a ratio of the lengths of two independent cycles. When the parameter
is a rational number, the space is asymptotically stretched along a cycle while
the other cycle kept finite. When the parameter is an irrational number, the
lengths of two cycles, as well as the space volume (area), grow in proportion
to the proper time $t$ for an observer sitting at rest in this universe in the
asymptotic region.
