  Theoretical predictions are given for the light-flavor sea-quark
distributions including the strange quark ones on the basis of the flavor SU(3)
version of the chiral quark soliton model. Careful account is taken here of the
SU(3) symmetry breaking effects due to the mass difference between the strange
and nonstrange quarks. This effective mass difference $\Delta m_s$ between the
strange and nonstrange quarks is the only one parameter necessary for the
flavor SU(3) generalization of the model. A particular emphasis of study is put
on the {\it light-flavor sea-quark asymmetry} as exemplified by the observables
$\bar{d} (x) - \bar{u} (x), \bar{d} (x) / \bar{u} (x), \Delta \bar{u} (x) -
\Delta \bar{d} (x)$ as well as on the {\it particle-antiparticle asymmetry} of
the strange quark distributions represented by $s (x) - \bar{s} (x), s (x) /
\bar{s} (x), \Delta s (x) - \Delta \bar{s} (x)$ etc. As for the unpolarized
sea-quark distributions, the predictions of the model seem qualitatively
consistent with the available phenomenological information provided by the NMC
data for $\bar{d} (x) - \bar{u} (x)$, the E866 data for $\bar{d} (x) / \bar{u}
(x)$, the CCFR data and Barone et al.'s fit for $s (x) / \bar{s} (x)$ etc. The
model is shown to give several unique predictions also for the spin-dependent
sea-quark distribution, such that $\Delta s (x) \ll \Delta \bar{s}(x) \lesssim
0$ and $\Delta \bar{d}(x) < 0 < \Delta \bar{u}(x)$, although the verification
of these predictions must await more elaborate experimental investigations in
the near future.
