With Gonocaryum lobbianum (Merr.) Kurz fruits as the raw material, the Gonocaryum lobbianum (Merr.) Kurz fruit oil were extracted by microwave-assisted extraction and supercritical CO2 fluid extraction, the chemical composition and relative content of each fatty acid of the oils by methyl esterifying using alkali catalyst and BF3-MeOH catalyst were identified by GC-MS. There was no significant difference of the chemical composition of the oils in these two extractions. A difference was methyl esterifying by alkali catalyst had identified seven kinds of fatty acids, whereas methyl esterifying by BF3-MeOH catalyst had identified ten. In the following four methyl esterifying ways: MAE(alkali catalyst), SFE-CO2(alkali catalyst), MAE(BF3-MeOH catalyst),SFE-CO2(BF3-MeOH catalyst), the highest content of fatty acids was octadecenoic acid (69.44%, 69.04%, 64.92%, 64.69%) , followed by hexadecanoic acid (20.82%, 21.01%, 21.69%, 21.45%), then octadecadienoic acid (6.33%, 6.03%, 6.33%, 6.13%). The total content of unsaturated fatty acids was 76.75%, 75.91%, 74.77% and 74.30% respectively．