The Raman cross-sections of β-carotene C=C double bond （1520 cm－1） and C—C single bond（1155 cm－1） vibration mode have been measured using cyclohexane as internal standard. The result shows that the Raman cross-section of β-carotene increases with the increase of refractive indexes of solvents. The difference of β-carotene Raman cross-section in different refractive indexes of solvents was explained by the dispersion and resonance Raman theory.