Abstract: The determination of quantitative factors for 9 geochemically relevant gases by FTRaman microprobe is reported in this paper. The results are 2.25 for H2, 1.06 for SO2, 1.13 for CO2, 0.91 for O2, 0.87 for CO, 1.00 for N2, 3.11 for H2S, 8.42 for CH4 and 3.