In this paper, new stimulated Brillouin scattering (SBS) medium of perfluoro-compound with low absorption and high power-load are reported. The choosing of medium for conjugation mirror (PCM) and optical limiting are discussed respectively, and validated in the Nd: YAG Q-switched laser system. The results indicate that medium with small molecular weight, low kinematic viscosity and large gain coefficient should be chosen for SBS PCM; however, medium with large molecular weight, great kinematic viscosity and small gain coefficient is needed in the optical limiting. The discovery of the new medius diversifies the SBS media and the medium choosing rules provide a guide to the application the new medium.