  To sustain a neutron star with about two times the solar mass, multi baryons
including hyperons are expected to produce repulsive effects in the interior of
its high baryon-density region. To examine possible quark-Pauli repulsion among
the baryons, we solve the eigenvalue problem of the quark antisymmetrizer for
three octet-baryons that are described by most compact spatial configurations.
We find that the Pauli blocking effect is weak in the $\Lambda nn$ system,
while it is strong in the $\Sigma^-nn$ system. The appearance of the $\Sigma^-$
hyperon is suppressed in the neutron star interior but no quark-Pauli repulsion
effectively works for the $\Lambda$ hyperon.
