  In this work, we first use Thompson's renormalization group method to treat
QCD-vacuum behavior close to the regime of asymptotic freedom. QCD-vacuum
behaves effectively like a "paramagnetic system" of a classical theory in the
sense that virtual color charges (gluons) emerge in it as spin effect of a
paramagnetic material when a magnetic field aligns their microscopic magnetic
dipoles. Making a classical analogy with the paramagnetism of Landau's
theory,we are able to introduce a kind of Landau effective action without
temperature and phase transition for simply representing QCD-vacuum behavior at
higher energies as magnetization of a paramagnetic material in the presence of
a magnetic field H. This reasoning allows us to use Thompson's heuristic
approach in order to extract an "effective susceptibility" ($\chi>0$) of
QCD-vacuum. It depends on logarithmic of energy scale u to investigate hadronic
matter. Consequently,we are able to get an "effective magnetic permeability"
($\mu>1$) of such a "paramagnetic vacuum". As QCD-vacuum must obey Lorentz
invariance,the attainment of $\mu>1$ must simply require that the "effective
electrical permissivity" is $\epsilon<1$,in such a way that $\mu\epsilon=1$
(c^2=1).This leads to the antiscreening effect, where the asymptotic freedom
takes place. On the other hand, quarks cofinement, a subject which is not
treatable by perturbative calculations, is worked by the present approach. We
apply the method to study this subject in order to obtain the string constant,
which is in agreement with the experiments.
