A novle surface plasmon resonance（SPR）sensor consisting of four layers high refractive index of LiNbO3 optical waveguide is proposed.The TM mode dispersion formula is inferred by using transfer matrix method.The relationship between waveguide effective refractive index and refractive index of sample

and the relationship between the waveguide transport constants and wavelength are studied

the SPR wavelengths versus refractive indices of sample are achieved by SPR coupling conditions.The transmission spectrum of the SPR are calculated.Simulation computational results indicate that the resonance wavelengths of SPR sensor with high refractive index LiNbO3 optical waveguide move to shortwave direction compared to the SPR sensor with low refractive index of glass waveguide in the same refractive index of sample

and it has large measurement of refractive index range.