In the present work,the Raman spectra of SO2-4 ions in aqueous solutions were studied.The quantitative analysis shows that there is a significant correlation between the Raman intensity ratio(R) and the SO2-4 concentration.The SO2-4 concentration in aqueous solution at ambient temperature and pressure can be determined by the Raman intensity according to the linear fitting equation ｃ(SO2-4)=4.779 6R(r2=0.999 4).Furthermore,the research proves that the temperature and pressure will affect the relationship between the Raman intensity ratio and the concentration of SO2-4 ions.The quantitative equation for measuring the SO2-4 concentration in aqueous solution at high temperature and high pressure is ｃ(SO2-4)=4.779 6(R+1.469×10-4ΔT+1.340×10-4ΔP),where R is defined as the ratio of the SO2-4 ions band intensity to the OH stretching single band intensity,ΔT is the temperature relative to 23 ℃,ΔP is the pressure relative to 0.1 MPa,23 ℃≤T≤390 ℃,the concentration range of the SO2-4 ions is 0.5～1.5 mol·L-1,and the uncertainty of the equation is 6.5%.Raman spectroscopy can be used to measure the concentration of the Raman-active species in aqueous solutions.