  Most of the inflation models end up with non-vanishing vacuum expectation
values of the inflaton fields \phi in the true vacuum, which induce, in
general, nonvanishing auxiliary field G_\phi for the inflaton potential in
supergravity. We show that the presence of nonzero G_\phi gives rise to
inflaton decay into a pair of the gravitinos and are thereby severely
constrained by cosmology especially if the gravitino is unstable and its mass
is in a range of O(100) GeV \sim O(10) TeV. For several inflation models, we
explicitly calculate the values of G_\phi and find that most of them are
excluded or on the verge of being excluded for the gravitino mass in that
range. We conclude that an inflation model with vanishing G_\phi, typically
realized in a chaotic inflation, is favored in a sense that it naturally avoids
the potential gravitino overproduction problem.
