  We study non-perturbative gluon pair production from arbitrary time dependent
chromo-electric field E^a(t) with arbitrary color index a =1,2,...8 via
Schwinger mechanism in arbitrary covariant background gauge \alpha. We show
that the probability of non-perturbative gluon pair production per unit time
per unit volume per unit transverse momentum \frac{dW}{d^4xd^2p_T} is
independent of gauge fixing parameter \alpha. Hence the result obtained in the
Fynman-'t Hooft gauge, \alpha=1, is the correct gauge invariant and gauge
parameter \alpha independent result.
