  We compute the O(alpha_s) SUSY-QCD corrections to the W and charged Higgs
mediated inclusive semi-tauonic B-decay, B->tau antineutrino_tau X. Combining
the SUSY contribution with the SM result obtained from the heavy quark
effective field theory, plus ordinary QCD corrections, we find that the allowed
region in the (tan(beta),M_H^\pm)-plane could be significantly modified by the
short-distance supersymmetric effects. Since the sensitivity to the SUSY
parameters other than mu (the higgsino mixing mass) is rather low, the
following effective bound emerges for mu<0 at the 2 sigma level: tan(beta)~<
0.43 (M_H^\pm/GeV). Remarkably, for mu>0 there could be no bound at all.
Finally, we provide a combined (tan(beta,M_H^\pm) exclusion plot using our
B-meson results together with the recent data from top quark decays.
