  Asteroseismology provides a powerful way to constrain stellar parameters.
Solar-like oscillations have been observed on subgiant stars with the
\emph{Kepler\/} mission. The continuous and high-precision time series enables
us to carry out a detailed asteroseismic study for these stars. We carry out
data processing of two subgiants of spectral type G: KIC 6442183 and KIC
11137075 observed with the \emph{Kepler} mission, and perform seismic analysis
for the two evolved stars. We estimate the values of global asteroseismic
parameters: $\Delta\nu=64.9\pm 0.2 $ $\mu$Hz and $\nu_{\rm max}=1225 \pm 17$
$\mu$Hz for KIC 6442183, $\Delta\nu=65.5\pm 0.2 $ $\mu$Hz and $\nu_{\rm
max}=1171 \pm 8$ $\mu$Hz for KIC 11137075, respectively. In addition, we
extract the individual mode frequencies of the two stars. We compare stellar
models and observations, including mode frequencies and mode inertias. The mode
inertias of mixed modes, which are sensitive to the stellar interior, are used
to constrain stellar models. We define a quantity $d\nu_{\rm m-p}$ that
measures the difference between the mixed modes and the expected pure pressure
modes, which is related to the inertia ratio of mixed modes to radial modes.
Asteroseismic together with spectroscopic constraints provide the estimations
of the stellar parameters: $M = 1.04_{-0.04}^{+0.01} M_{\odot}$, $R =
1.66_{-0.02}^{+0.01} R_{\odot}$ and $t=8.65_{-0.06}^{+1.12}$ Gyr for KIC
6442183, and $M = 1.00_{-0.01}^{+0.01} M_{\odot}$, $R = 1.63_{-0.01}^{+0.01}
R_{\odot}$ and $t=10.36_{-0.20}^{+0.01}$ Gyr for KIC 11137075. Either mode
inertias or $d\nu_{\rm m-p}$ could be used to constrain stellar models.
