  We briefly review the QCD physics and then introduce recent topics on the
confinement physics. In the maximally abelian (MA) gauge, the low-energy QCD is
abelianized owing to the effective off-diagonal gluon mass $M_{\rm off} \simeq
1.2 {\rm GeV}$ induced by the MA gauge fixing. We demonstrate the construction
of the dual Ginzburg-Landau (DGL) theory from the low-energy QCD in the MA
gauge in terms of the lattice QCD evidences on infrared abelian dominance and
infrared monopole condensation.
