A Visible absorption and Raman spectra of all-trans-β-carotene was measured in cyclohexanol solution in the temperature range from 68 ℃ to 26 ℃. The results indicated that the visible absorption spectra are red-shifted, Raman scattering cross section increases, Huang-Ryes factor and electron-phonon coupling constants of CC bond vibration modes decreases with the temperature decreasing. The changes are interpreted using the theory of “coherent weakly damped electronic-lattice vibration model” and “effective conjugation length model”. The red shift of the absorption spectra and intensity of the Raman active are attributed to the thermal conformational change-induced increase in the effective conjugation length in all-trans-β-carotene chains. All-trans-β-carotene has strong coherent weakly damped CC bonds vibrational properties, which lead to large Raman scattering cross section in the solvent of low temperature. The electron-phonon coupling constants with dimension are used, which can easily establish relation with the Huang-Rhys factor and calculate the electron-phonon coupling constants of CC bond vibration modes. Effective conjugation length, the π-electron delocalization range and the Raman scattering cross section are described by the electron-phonon coupling constants.