Vibrational Raman spectra of the C=C stretching modes of cis-stilbene and cis-1,2-dichloroethylene (C2H2Cl2) were measured in supercritical CO2 in a density range of 0.08 < p(r) = p/pc < 1.5 at an isotherm of T-r = TIT, = 1.02. As the fluid density increased, the peak frequencies of cis-stilbene and cis-C2H2Cl2 shifted toward the low-energy side. The shifted frequencies of cis-stilbene were consistently greater than those of cis-C2H2Cl2 in all density regions, by a factor of 4. By analyzing these density dependencies using the perturbed hard-sphere theory, the shifted frequencies were decomposed into attractive and repulsive components. By quantifying these components as a function of fluid density, we investigated how each solute is solvated in supercritical CO2. The results indicate that the attractive energy between cis-stilbene and CO2 is twice that between cis-C2H2Cl2 and CO2. A local density augmentation around the solute molecule was not observed in the cis-C2H2Cl2/CO2 system, but it was observed in the cis-stilbene/CO2 system because of site-selective solvation around the phenyl group of cis-stilbene. To the best of our knowledge, this is the first time that the site-selective solvation of a solute molecule has been observed using Raman spectral measurements of a solution system. Based on theoretical calculations and Raman spectral measurements of cis-stilbene in the supercritical fluid of dipolar CHF3, it is concluded that a driving force for site-selective solvation is the dispersion force.