Abstract: In order to explore the relationship between the change of characteristic functional groups and the complex shear modulus of asphalt binder after repeated water-temperature cycles in seasonal frozen area, the SBS modified asphalts binders after 0, 3, 6, 9, 12, 15 and 18 times water-temperature cycles were tested by combing FTIR with dynamic shear rheological (DSR) testing techniques. The disciplinarian of complex shear modulus and the characteristic function groups of styrene-butadiene-styrene (SBS) modified asphalt binder under multiple water-temperature cycles were ascertained. Correlation between the complex shear modulus and the content of the characteristic functional groups was clarified based on the mathematical model of gray relational entropy analysis. Multivariate statistical regression analysis of the complex shear modulus G^* of the SBS modified asphalt binder and the change functional group index by FTIR test under different temperatures and frequencies were conducted based on the Levenberg-Marquardt method and the generalized global optimization algorithm, and the prediction model of complex shear modulus of SBS modified asphalt binder was proposed. The results show that the asphalt binder has been aged after multiple water-temperature cycles, but SBS modifier has inhibitory effect on asphalt aging. The sulfoxide and carbonyl groups in the FTIR spectra of asphalt binder show an obviously increasing tendency with the increases of water-temperature cycles. The aliphatic is the highest of the six for SBS modified asphalt characteristic functional groups changes on the complex shear modulus impact, with the asymmetric aliphatic, aromatic compounds, styrene plus butadiene, sulfoxide and carbonyl following. The complex shear modulus of the SBS modified asphalt binder after multiple water-temperature cycles shows a multiple linear relationship with the change of characteristic functional groups.