  We report on a theoretical investigation concerning the polaronic effect on
the transport properties of a charge carrier in the one-dimensional molecular
chain. Our technique is based on the Feynman's path integral approach.
Analytical expressions for the frequency-dependent mobility and effective mass
of the carrier are obtained as functions of electron-phonon coupling. The
result exhibits the crossover from a nearly free particle to a heavily trapped
particle. We find that the mobility depends on temperature and decreases
exponentially with increasing temperature at low temperature. It exhibits
large-polaronic-like behaviour in the case of weak electron-phonon coupling.
These results agree with the phase transition \cite{Mish} of transport
phenomena related to polaron motion in the molecular chain.
