Stimulated Raman scattering (SRS) has been an important method in the tunable laser frequency since it has the characteristics of the laser beams and easily acquires different wavelengths. However, the practical application of SRS is limited because of its low conversion efficiency. Metal nanoparticles have been widely used in the surface-enhanced Raman scattering (SERS) as they have very strong surface enhancement effect. In this article, metal nanoparticles are employed to improve the conversion efficiency of SRS. Au nanoparticles are mixed in the Raman medium acetone, and the nanosecond pulse laser of 532 nm is used as the pump source of the SRS. The first Stokes intensity of the SRS evolving with the concentration of Au nanoparticles in acetone is studied, and the experimental results are explained and analyzed by simulated calculations.