  We study the charged Higgs effects on the decays of $B^{-} \to \tau
\bar\nu_{\tau}$ and $\bar B\to P(V) \ell \bar\nu_{\ell}$ with $P=\pi^{+},D^{+}$
and $V=\rho^{+},D^{*+}$. We concentrate on the minimal supersymmetric standard
model with nonholomorphic terms at a large $\tan\beta$. To extract new physics
contributions, we define several physical quantities related to the decay rate
and angular distributions to reduce uncertainties from the QCD as well as the
CKM elements. With the constraints from the recent measurement on the decay
branching ratio of $B^{-} \to \tau \bar\nu_{\tau}$, we find that the charged
Higgs effects could be large and measurable.
