  The entropy production rate of nonequilibrium systems is studied via the
Fokker-Planck equation. This approach, based on the entropy production rate
equation given by Schnakenberg from a master equation, requires information of
the transition rate of the system under study. We obtain the transition rate
from the conditional probability extracted from the Fokker-Planck equation and
then derive a new and more operable expression for the entropy production rate.
Examples are presented as applications of our approach.
