Abstract: For identifing Dalbergia odorifera and D. tonkinensi accurately, the volatile components and fat-soluble ingredients of D. odorifera and D. tonkinensi are tested with gGC-MS. In detecting volatile components, equilibrium temperature of headspace sampler was one of the main factors that the volatile substance species and quantity increased with increasing of the equilibrium temperature. These two wood species share more than 30 kinds of volatile components with great similarity but little difference in content, which was not characteristic for identification.In detecting fat-soluble ingredients ethyl acetate was the best extraction reagent. Both wood species occupied many similar and different fat-soluble ingredients. Similar ingredients included large amounts of 3,7,11-trimethyl-1,6,10-dodecatrien-3-ol,(6Z)3,7,11-trimethyl-1,6,10-dodecatrien-3-ol and 6,7-epoxide humulene(6Z), which accounted for more than 40% of the total fat-soluble ingredients.D. tonkinensi occupies 5 ingredients with higher content which amount up to 20%-40% of total fat-soluble substance, namely, 3,3',4,4'-tetra-methoxystilbene, 5,7-dihydroxyflavanone, 3-(2,4-dimethoxyphenyl)-7-methoxychroman, 3,4-dihydro-7-methoxy-3-(2,3,4-trimethoxyphenyl)-2H-1-benzopyran and N-[2-(3,4-dimethoxyphenyl)ethyl]-3-methoxy-benzamide. However, these substance add up to less than 1% in D. odorifera, making these two species differentiable. In a word, volatile components resemble but fat-soluble ingredients differed distinctly, which was the basis for identification of D. odorifera and D.tonkinensi with GC-MS.