  It is proved that in order to keep both the Lagrangian and the motion
equation of non-Abelian gauge fields unchanged under the gauge transformation
simultaneously, a certain restriction conditions should be established between
the gauge potentials and the group parameters. The result is equivalent to the
Faddeev--Popov theory. For non-Abelian gauge fields, it leads to the result
that the gauge potentials themselves are unchanged under gauge transformations.
In this way, the mass items can be added into the Lagrangian directly without
violating gauge invariability and the theory is also renormalizable so that the
Higgs mechanism becomes unnecessary. The description of gauge theory also
becomes more symmetrical and simple.
