Several different size Al₂O_3nano -particles with high dispersion were doped into acrylamide based photopolymer materials,and the photopolymers were exposured with 647nm Ar⁺Kr⁺ laser to s tudy the holographic properties.The results show that the incorporation of Al₂O_3nano-particle leads to a significant improvement of the holographic characteristics,and the polymer photochemical reaction can be promoted.At the same time,through the surface m odification of Al₂O_3nano-particles with the dispersant,the effect of clusters can be reduced and the dispersion increas es.After the photopolymers were exposured,the permanent refractive index grating can be formed owing to a spatial distribution of the effective refractive index with periodically distributed Al₂O_3nano-particles and polymerized monomers during the hologr aphic recording.There is a structure formed just like the skeleton in the polymer,which can inhibit the shrin kage and improve the optical properties of materials, such as the diffraction efficiency and the Bragg mismatch.Additionally,there exi sts the optimum concentration of Al₂O_3nano-particles,the maximum diffraction efficiency of the sample can be raised from 52.6% to 93.8%,the volume shrinkage can be depressed to 0.8% while the the average size of Al₂O_3nano-part icles is about 10nm and the concentration of Al₂O_3is 1.02×10－3 mol /L.