Sizes of ginseng seeds and contents of ginsenosides, free sugars and fatty acids in the seeds were investigated at different dates after flowering of 4 year old ginseng to get basic information used for determining harvest . time of ginseng seed. The sizes of seeds were maximum about 35 days after flowering(DAF), while those of endosperms reached maximum at 50 DAF. At 65 DAF seeds with intact pulp weighed most heavy. The amounts of total saponin and ginsenosides were decreased with time after flowering. Contents of free sugars such as glucose, maltose and fructose were decreased continously after flowering. Amount of palmic acid was decreased, .but those of oleic, linoleic and stearic acids were increased with time after flowering.