The fatty acid of leaf and stems bark of Glycosmis petelotii collected from Pu Huong Natural Reserve, Nghe An province in Vietnam was analyzed by Capillary GC and GCIMS. Seven and Six components have been identified, accounting for 80.71 percent and 84.27 percent of the fatty oil. The major constituents are (Z)-13-docosenamide (52.65-57.81 percent) and (Z)-9-octadecenamide (21.58-22.25 percent). Less predominant constituents induded n-hexadecanoic acid (1.25-1.29 percent), octadecanoic acid (1.47-1.51 percent), 1,2-benbenzenedicarboxylic acid (0.63-1.48 percent) and n-einicosane (1.13-1.45 percent).