  We study how the initial inhomogeneities of the spatial curvature affect the
onset of inflation in the closed universe. We consider a cosmological model
which contains a radiation and a cosmological constant. In order to treat the
inhomogeneities in the closed universe, we improve the long wavelength
approximation such that the non-small spatial curvature is tractable in the
lowest order. Using the improved scheme, we show how large inhomogeneities of
the spatial curvature prevent the occurrence of inflation.
