To determine the fatty acid composition in the oil of Semen Momordicae to evaluate itspractical use. Fatty oil was obtained by Soxhlet extraction with petroleum ether and converted to methylester derivatives by methanolic potassium hydroxide. Contents of the resultant methyl esters were then de-termined by GC-MS. Eight fatty acids were characterized and determined. Results of the study may pro-vide some information for the exploitation and utilization in the oil of seed of Momordicae cochinchinensis(Lout.) Spreng.