Two kinds of spectrum, the Raman-Induced Kerr Effect Spectrum(RIKES)and the Photoacoustic Raman Spectrum(PARS),were measured simultaneously for the ν1 vibrational band of methane. The difference between the profiles of the two spectra obtained with linearly polarized pump and Stokes laser beams lies in that, the intensity of RIKES spectrum is stronger at the small Raman shift side, and is weaker at the large Raman shift side compared to the PARS spectrum. It was confirmed that this difference is caused by the interference between the resonant and non-resonant parts of the third order non-linear susceptibility.