An insulator-metal-insulator filter based on Surface Plasmon Resonance (SPR) and photorefractive (PR) grating in Lithium niobate (LiNbO_{3) is designed. Through numerical simulation by using two-dimensional finite element method, incident angle of 46.399 5° for stimulating SPR was calculated at a fixed wavelength 656 nm. On the basis of definition of complex refractive index, sensitivity of SPR wavelength to half angle of dual beam was theoretically derived. Finally, under different grating periods in LiNbO3, reflection spectrum of SPR stimulated from a broadband light source was studied. The results show wavelengths corresponding to SPR are filtered and the SPR wavelengths shift when the period of PR grating is changed. The designed device is expectable for tunable filtering.作者简介：张明(1975-)，男(汉族)，河北唐山人。博士，副教授，主要从事光通信器件和光电}