  The dependence of function renormalization group equation on regulators is
investigated. A parameter is introduced to control the suppression of
regulators. Functional renormalization group equations will become
regulator-independent if this newly introduced parameter is sent to infinity in
the end of calculation. One-loop renormalization flow equations of QCD are
derived. The novelty is that both the coupling running equation and the mass
running equation are mass-dependent. Different flow patterns are explored. A
mechanism for non-occurrence of dynamical chiral symmetry breaking is arrived
at. The existence of a conformal window is also discussed in the language of
renormalization flow.
