The quantum-chemical study of spectral and photophysical properties of o-, m- and p-toluidines by the PNDO method with spectroscopic parameterization has been carried out. The rate constants of photophysical processes have been calculated. The features in the effect of the position of methyl group in the phenyl radical and electronic excitation on the proton-donating and proton-accepting properties of substituted aniline have been revealed.