  Inflationary potentials are investigated for specific models in type IIB
string theory via flux compactification. As concrete models, we investigate
several cases where the internal spaces are weighted projective spaces. The
models we consider have two, three, or four K\"{a}hler moduli. The K\"{a}hler
moduli play a role of inflaton fields and we consider the cases where only one
of the moduli behaves as the inflaton field. For the cases with more than two
moduli, we choose the diagonal basis for the expression of the Calabi-Yau
volume, which can be written down as a function of four-cycle. With the
combination of multiple moduli, we can express the multi-dimensional problem as
an effective one-dimensional problem. In the large volume scenario, the
potentials of these three models turn out to be of the same type. By taking the
specific limit of the relation between the moduli and the volume, the
potentials are reduced to simpler ones which induce inflation. As a toy model
we first consider the simple potential. We calculate the slow roll parameters
$\epsilon$, $\eta$ and $\xi$ for each inflationary potential. Then, we check
whether the potentials give reasonable spectral indices $n_s$ and their running
$\alpha_s$'s by comparing with the recently released seven-year WMAP data. For
both models, we see reasonable spectral indices for the number of e-folding
$47<N_e<61$. Conversely, by inserting the observed seven-year WMAP data, we see
that the potential of the toy model gives requisite number of e-folds while the
potential of the K\"{a}hler moduli gives much smaller number of e-folding.
Finally, we see that two models do not produce reasonable values of the running
of the spectral index.
