Tremendous studies have been accumulated on the tonic effects of the ginseng to date. They are temporary effects on the heart, blood, kidney, liver, spleen etc. during the ginseng-administered period. After this period, however, theses transient effects were completely abolished soon or later. Time-honored continuous tonic effects of ginseng remained mystic. In 1975, author reaffirmed histological changes on the ventromedial nuclei of the appetite center resulting voracious appetite and weight-gain in gold-thioglucose injected mice. It was evident that "the irreversible tissue changes" could explain "continuous" effects on the appetite and weight-gain. This study was performed to observe whether ginseng evokes histological changes on the appetite center of the hypothalamus or not. Materials and Method: A total of 53 albino mice of both sexes were fed with commercial rodent feed; 12 out of 53 were fed contrast group, 13 were fed adding 1% of ginseng powder for 4 weeks; 14, 2% and the other 14, 4% respectively. All of experimental groups were fed with rodent feed not containing ginseng for further 8 weeks until sacrificed. Results: Group fed roden feed with 2% ginseng powder showed weight-gain in comparision with the other groups. The difference of body weight, however, gradually decreased and became slight at the end of 8 weeks. Macro-and microscopically, there was no significant histological change between the each group although some questionable increase or decrease of diffuse hypothalamic cell groups including both feeding and satiety centers. Conclusion: The significant histological change did not develop on the appetite center with administration of the ginseng powder for 4 weeks in the mice.