The hair-growth effect of Illite was suggested by some people who were using Illite as a beautifying material. We investigated the hair-growth effect of Illite powder. The hair-growth effects were investigated by two methods; the activity of hair-growth after shaving the hairs on the black mouse (C57BL/6) and the recovery activity of hair-growth after hair-loss induced by cyclophosphamide treatment. Suspension of Illite powder was applied to the back of the black mouse by method of skin paste. Illite promoted significantly the hair growth of mouse in both conditions of shaving and hair-loss. And then we investigated the toxicity which may be induced by Illite when it was administrated orally as a single dose. We could not fond out any significant toxicity induced by single dose oral administration of Illite.