  Inspired by the discovery of two pentaquarks $P_{c}(4380)$ and $P_{c}(4450)$
at the LHCb detector, we study possible hidden-charm molecular pentaquarks in
the framework of quark delocalization color screening model. Our results
suggest that both $N\eta_{c}$ with $IJ^{P}=\frac{1}{2}\frac{1}{2}^{-}$ and
$NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ are bounded by channels
coupling. However, $NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ may be a
resonance state in the $D-$wave $N\eta_{c}$ scattering process. Moreover,
$P_{c}(4380)$ can be explained as the molecular pentaquark of $\Sigma^{*}_{c}D$
with quantum numbers $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$. The state
$\Sigma^{*}_{c}D^{*}$ with $IJ^{P}=\frac{1}{2}\frac{5}{2}^{-}$ is a resonance,
it may not be a good candidate of the observed $P_{c}(4450)$ because of the
opposite parity of the state to $P_{c}(4380)$, although the mass of the state
is not far from the experimental value. In addition, the calculation is
extended to the hidden-bottom pentaquarks, the similar properties as that of
hidden-charm pentaquarks system are obtained.
