Deep sea water is sea water below a depth of 200 m. Japan is the leading country in the world on industrial applications of deep sea water, which has characteristics such as cleanliness, and is rich in various kinds of minerals and inorganic nutrients compared to surface seawater. In addition, applications of deep sea water as a useful resource have become a world interest, especially in fields of presymptomatic diseases called mibyo and in preventive medicine. Evidence of deep sea water applications in experimental and clinical medicine of the following diseases, lifestyle diseases such as dyslipidemia, high blood pressure, diabetes and arteriosclerosis and atopic dermatitis, osteoporosis, cancer, peptic ulcer, cataracts and constipation are given particular attention in this review.