Torsional vibronic bands of the methyl group of m-tolunitrile-H2O and m-tolunitrile-N2O complexes in their S, (first excited singlet electronic) states were observed under the supersonic-jet condition by laser-induced fluorescence and hole-burning spectroscopies. Torsional potentials determined from the observed frequencies revealed that the complex formation similarly affects for the H2O and N2O complexes. Two isomers were assumed for both the H2O and the N2O complexes: One showed vibrational frequencies of torsion similar to those of the monomer, whereas torsional potentials for the other complexes were lower than that in the monomer and of nearly 6-fold symmetry. The geometries of the complexes were evaluated by molecular-orbital calculations.