Raman spectra of CO2 fluids were measured at 288-329 K and densities of 0.81-1.16g/cm(3). The peak area ratios of hot bands at 1265 and 1408 cm(-1) and Fermi doublet peaks at 1388 and 1285 cm(-1) were correlated linearly with temperature. The peak area ratios are correlated with density. Calculation of the relationship between the peak area ratio, temperature, and density was achieved. Micro-Raman analysis enabled in situ temperature measurement of CO2 fluid with high spatial resolution.