We study the charged Higgs effects on the decays of B − → τν τ and B → P (V ) ν with P = π + , D + and V = ρ + , D * + . We concentrate on the minimal supersymmetric standard model with nonholomorphic terms at a large tan β. 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 − → τν τ , we find that the charged Higgs effects could be large and measurable.