  In this paper, we give the moderate deviation principle from the hydrodynamic
limit of the simple exclusion process on $1$-dimensional torus starting from a
nonequilibrium state, which extends the result given in Gao and Quastel (2003)
about the case where the process starts from an equilibrium state. The
exponential tightness of the scaled density field of the process and a
replacement lemma play key roles in the proof of the main result. We utilize
Grownwall's inequality and the upper bound of the large deviation principle
given in Kipnis, Olla and Varadhan (1989) to prove above exponential tightness
and replacement lemma respectively in the absence of the invariance of the
initial distribution.
