Abstract: During holographic recording, mixed gratings in photopolymer doped with gold nanoparticles are formed by the primary refractive index grating caused by periodic spatial distribution of photoproduct and the secondary absorption grating induced by spatial distributed nanoparticles because of local surface plasmon resonance. A mixed-grating model based on Kogelnik's coupled wave theory was investigated to analyze the volume holographic characteristics. Results show that both refractive index grating and absorption grating contribute to the improvement of diffraction efficiency; the mixed gratings also exert positive influence on angular selectivity.