The variation characters of Raman spectra of S—O symmetric stretching vibration ν987 and symmetric bending vibration ν452 and ν462 of barite at high pressure were studied using moissanite anvil cell. The experimental results show that barite is stable at the pressure of 0～1 GPa and ambient temperature, and the Raman peak positions of barite shift to higher frequency with increasing pressure. The relations between the Raman shifts and system pressure are given as follows: ν987=0.004 4p+987.42, ν452=0.002 3p+452.6, ν462=0.001 8p+462.42, and that stretching vibrations are more affected by pressure than bending vibrations. The intensity of 987 cm-1 Raman peak of barite is six times greater than that of 464 cm-1 Raman peak of quartz, so barite can be used as a good pressure gauge. Besides, the relation between the system pressure and Raman shift of 987 cm-1 peak position of barite is given as follows: p(MPa)=223.16×(Δνp)987－90.35(987 cm-1＜νp＜992 cm-1). The difference in the measured relative pressure-shift of the Raman line of the symmetric stretching vibration among various sulfate minerals shows the compressibility and strength of the S—O bond in the SO4 group.