  We study the decays of the charged Higgs boson H^+ within the Minimal
Supersymmetric Standard Model. We find that the supersymetric mode 'stop +
sbottom-bar' can dominate the H^+ decays in a wide range of the model
parameters due to the large Yukawa couplings and mixings of stop and sbottom.
Compared to the conventional modes 'tau^+ nu' and 't b-bar', this mode has very
distinctive signatures. This could have a decisive impact on H^+ searches at
future colliders. We find also that the QCD corrections to the 'stop +
sbottom-bar' mode are significant, but that they do not invalidate our
tree-level conclusion above.
