There are several methods for birefringence measurement such as ellipsometer and optical coherence tomography. A novel method for birefringence measurement is proposed. The waveguide-mode resonance is excited by leaky radiation-mode microscope with azimuthally polarized beam illumination. By observe the Fourier spectrum on back focal plane, the birefringence character can be measured. The principle of birefringence measurement with this method is analyzed and the photo-induced birefringence about Δn≈0.005 of azobenzene (AZO) polymer film is measured, which can achieve high sensitivity and high spatial resolution birefringence measurement.