Abstract: An experimental investigation on diffraction of two different polarized incident lights in C60-doped Nematic Liquid Crystal (NLC) homeotropically aligned is reported. The experiment shows that much greater energy transfer is created in grating recorded by horizontal polarization (P-P polarization) beams than that by vertical polarization (S-S polarization) ones, and the energy transfer direction is totally opposite. It is shown that when one incident beam polarization state is changed, the intensity of diffraction and transmitted beam will be changed accordingly after the grating is written. The polarization state is a very important parameter in the determination of nonlinear reorientation NLC. Nonlinear phenomena caused by molecular reorientation and their dependence on light polarization should be very useful in potential applications for optoelectronic functional elements.