The natural rubber seed oil was extracted by The supercritical fluid CO2 technology. The contents of fatty acids in The natural rubber seed oil were determined by means of GC normalization. Its unknown components were tested and identified by The method of GC/MS. The rubber seed oil extracted by The Supercritical Fluid CO2(SFE- CO2) was compared with The one extracted by The method of Soxhlet. The results show that 12 kinds of fatty acids in The rubber seed were determined, and The contens of α-18:3 and γ-18.3, which have great value, were respectively 18.74% and 0.70%. The rubber seed oil extracted by SFE- CO2 has no organic solvent, and are nonpoisonous and harmless. Its GC graph is plain and has less miscellaneous peaks and The contents of γ-18:3 is 4 times more than that extracted by The method of Soxhlet. In addition, The fatty acid contents of ≥ 3 alkene bonds were significantly decreased after The sample of The fatty acid methyl ester was placed in a refrigerator more than 3 months.