Coherent Anti-Stokes Raman Scattering (CARS) is a stimulated Raman process, which has the non-resonant background (NRB), leading to peak shift and spectral distortion in the spectrum. In this letter, we use a femtosecond laser as the light source and a grating filter system generating narrow-band pump light. The femtosecond laser excites photonic crystal fiber, producing a supercontinuum spectrum as Stokes light. Two beams excite the samples simultaneously after modulated to circular polarized lights to produce CARS spectrums. We illustrate that circularly polarized light can effectively remove the non-resonant background in the CARS spectrum of anisotropic materials by simulation. Thus, the CARS spectrum has a similar spectral line shape to that of spontaneous Raman. The experimental results of CARS spectrums of polystyrene and liquid crystal samples generally agree with the calculations, proving that circularly polarized CARS spectroscopy is an effective method to remove the NRB of CARS spectrum.