This investigation on the composition of fatty acids of hempseed through gas -chromatography analysis found the follwing results. Myristic acid and other ten materials were detected. And there was mainly composed of myristic acid 29.4%, Palmitoleic acid 16.2%, linoleic acid 14.9%, oleic acid 12.4%. It also showed that heptadecanoic acid 10.8%, erucic acid 0.5%, docosahexaenoic acid 0.3% and essential fatty acid were contained 11.9% between them. As stearic acid, docosahexaenoic acid, linoleic acid and arachidonic acid made lower cholesterol level in body, they will help prevention of senile disease with the oil d hemp seed.