Effect of red ginseng treatment on experimentally induced hyperkeratosis was investigated by light microscopic observation scanning electron microxcope (SEM) examination, epidermal enzyme activities nd lipid contents. Both light microscopic observation and SEM examination showed that hexadecane induced epidermal hyperplasia, hypertrophy and hyperkeratosis by increasing the numbers as well as the sizes of epidermal cells including desquamating horny cells. The superficial horny cells were protruded around the base of hair shaft. Among red ginseng components, only saponin treatment inhibited epidermal hyperplasia and hyperkeratosis by reducing the thickness of epidermis and arranging the cornified cells. Saponin from korean red ginseng inhibited abnormally increased epidermal LDH, ICD and G6PDH activities and reduced the contents of epidermal lipids induced by hexadecane. It seems that red ginseng saponin has preventive effect on experimental hyperkeratosis possibly by controlling the enzyme activities involved in epidermal cellular metabolism, resulting in reduced amounts of abnormal epidermal lipids.