  After taking account of the scale dependence by means of the standard DGLAP
evolution equation, the theoretical predictions of the chiral quark soliton
model for the unpolarized and longitudinally polarized structure functions of
the nucleon are compared with the recent high energy data. The theory is shown
to explain all the qualitative features of the experiments, including the NMC
data for $F_2^p (x) - F_2^n (x)$, $F_2^n (x) / F_2^p (x)$, the Hermes and NuSea
data for $\bar{d}(x) - \bar{u}(x)$, the EMC and SMC data for $g_1^p(x)$,
$g_1^n(x)$ and $g_1^d(x)$. Among others, flavor asymmetry of the longitudinally
polarized sea-quark distributions is a remarkable prediction of this model,
i.e., it predicts that $\Delta \bar{d}(x) - \Delta \bar{u}(x) = C x^{\alpha} [
\bar{d}(x) - \bar{u}(x)]$ with a sizable negative coefficient $C \simeq -2.0$
(and $\alpha \simeq 0.12$) in qualitative consistency with the recent
semi-phenomenological analysis by Morii and Yamanishi.
