The Raman spectra of CS2 in C6H6 is messured and the Fermi resonance of v1—2v2 in solution and in pure CS2 is obvionsly different.The characteristic parameters are calculated by Berttern equation.It was found that with the concentration of CS2 declining,the ratio of the spectral intensity （R=Ｉ655/I796） decreases and the coupling coefficient （Ｗ） raises, and the other parameters also change correspondingly.　The analysis shows that dissipation coefficient of v01 of CS2 is affected by the concentration of C6H6. Asymmetric frequency shift of v01 and 2v02 are observed in experiment,which is explained by amending the Bertran theory. This report has reference value for the molecule spectrum certification and the understanding and use of Fermi resonance theory.