On the basis of the concept of local composition, a new model is proposed for correlating the Raman frequency shifts of a C-H stretching band over the whole concentration with only one energy parameter. Mixtures investigated include water + acetone, water + 2-propanol, water + N,N-dimethylformamide (DMF), water + methanol, water + ethanol, water + 1,4-dioxane, water + dimethyl sulfoxide (DMSO), and water + acetonitrile systems. The vapor-liquid equilibrium data were predicted by the parameter obtained from the spectra and one activity coefficient at infinite dilution. In this way, the spectroscopic information can be,related to thermodynamic properties.