A novel temperature and salinity discriminative sensing method based on forward Brillouin scattering （FBS） in 1060-XP single-mode fiber （SMF） is proposed. The measured frequency shifts corresponding to different radial acoustic modes in 1060-XP SMF show different sensitivities to temperature and salinity. Based on the new phenomenon that different radial acoustic modes have different frequency shift-temperature and frequency shift-salinity coefficients， we propose a novel method for simultaneously measuring temperature and salinity by measuring the frequency shift changes of two FBS scattering peaks. In a proof-of-concept experiment， the temperature and salinity measurement errors are 0.12 ℃ and 0.29%， respectively. The proposed method for simultaneously measuring temperature and salinity has the potential applications such as ocean surveying， food manufacturing and pharmaceutical engineering.