Abstract
This paper models a system of cities which generates various spatial structures. The factors determinant to the structures, in particular, the transport network is to be examined. Since the model includes agglomeration economy and diseconomy, the system of equations is non-linear and therefore has to be solved in a not only analytical but also numerical way. The stability of spatial structure must be examined through the analysis.
As major findings in the analysis, it was verified that reduction of transport cost caused the structural change as dispersed → concentrated → dispersed again, and that there emerged an unstable structure under some combinations of parameter values.
