  Chiral symmetry in massless QCD is believed to be broken spontaneously. We
discuss a possibility that the chiral symmetry is explicitly broken by QCD
monopoles which appear only in strong coupled QCD. Namely, the monopole quark
interaction explicitly breaks the chiral symmetry ( SU$_A(2)\times $U$_A$(1) )
just like bare quark mass terms. We show that the strength of the interaction
is roughly $10$ times smaller than standard strong interactions. We describe it
as an effective interaction $g'\bar{q}q\Phi^{\dagger}\Phi$ with the monopole
field $\Phi$ and $g'$ being of the order of $(10\rm \,GeV)^{-1}$ or less. It
produces small constituent quark masses less than $1$MeV when the monopoles
condense ( $\langle\Phi\rangle\neq 0 $ ). We examine to what extent such a weak
but explicit symmetry breaking interaction is allowed. In particular, examining
Gell-Mann-Oakes-Renner relation we find that the presence of such a small
symmetry breaking term is still allowed within the present accuracy of lattice
gauge simulations. We predict some phenomenological effects caused by the
chiral nonsymmetric monopole quark interaction. Quark confinement and chiral
condensate ( $\langle\bar{q}q\rangle\neq 0$ ) arise simultaneously. The
condensate $\langle\bar{q}q\rangle$ caused by the monopoles is proportional to
monopole density and is estimated such that
$(-\langle\bar{q}q\rangle)^{1/3}\sim 160$MeV. The weak monopole quark
interaction leads to the small decay width of an observable monopole to
hadrons.
