The discrete dipole approximation (DDA) was used to investigate the effect of polarization on optical properties of single gold nanorod. The near-field distribution around the nanorod was obtained, which has some instructive significance for designing the nano-optical devices on the basis of metal nano and micro structure. The results show that different light polarization induce different surface plasmon mode (the transverse surface plasmon resonance and the longitudinal surface plasmon resonance), which influences extinction spectra and the near-field distribution of gold nanorod.