  Taking into account the helium and metal diffusion, we explore the possible
evolutionary status and perform seismic analysis of MOST target: the star
$\epsilon$ Eridani. We adopt the different input parameters to construct the
models by fitting the available observational constraints: e.g., $T_{eff}$,
$L$, $R$, $[Fe/H]$. From computation, we obtain the average large spacings of
$\epsilon$ Eridani about $194\pm 1 \mu$Hz. The age of the diffused models has
been found to be about 1 Gyr, which is younger than one determined previously
by models without diffusion. We found that the effect of pure helium diffusion
on the internal structure of the young low-mass star is slight, but the metal
diffusion influence is obvious. The metal diffusion leads the models to have
much higher temperature in the radiation interior, correspondingly the higher
sound speed in the interior of the model, thereby the larger frequency and
spacings.
