  Within the framework of a model Universe with variable space dimension, we
study chaotic inflation with the potential $m^2\phi^2/2$, and calculate the
dynamical solutions of the inflaton field, variable space dimension, scale
factor, and their interdependence during the inflationary epoch. We show that
the characteristic of the variability of the space dimension causes the
inflationary epoch in the variable space dimension to last longer than the
inflationary epoch in the constant space dimension.
