Localized surface plasmon resonance (LSPR) effect of gold nanoparticles could b e used to enhance the photoluminescence properties of silicon-rich silicon nitride (SRSN).The size a nd morphology of gold nanoparticles have significant influence on the light-emitting properties of t he devices.In this paper,the finite-difference time-domain (FDTD) method is applied to investigate the opt ical properties of gold nanoparticles with different sizes and morphologies.The size of gold nanopartic le only affects the LSPR strength, while the morphology affects both the LSPR wavelength and intensity.When the pa rticles become flat,the LSPR wavelength presents red shift and the LSPR becomes stronger.The LSPR based gold nanoparticles were fabricated on the surface of SRSN film.Raman spectroscopy,scanning electron microscopy (SEM) and O LYMPUS microscopy are employed to study the optical properties of SRSN light emitting devices with gold nanoparticles wi th varied size,shape and distribution. The results show that the photoluminescence intensity of SRNS light emitting dev ices could be enhanced by 7times at the wavelength of 570nm by optimizing the size,shape and distribution of gold nanoparticles.Meanwhile,the position of the enhancement peak has a 10nm red shift.