Cortex Mori radicis has been used as a components of antidiabetics, antiasthma and diuresis in Oriental Medicine. This experiment examined the effect of an extracts, obtained from the acetone(CM-A) and aqueous(CM-W) extracts of Cortex Mori radicis, on hair growing activity of the C57BL/6N mice after topical application to skin. We investigated the number of hair follicle and mast cells, and changes of subpopulation of splenocytes and thymocytes in skin for 16 day. The results were as follows : The Hair growing effect in experimental groups was more increased in 85%(CM-A) and 90%(CM-W) than control group(10%) in hair depilated area. The number of hair follicle in experimental groups(CM-A and CM-W) was more increased than control group. Splenic B/T lymphocytes of CM-A group were decreased compare to control group. CD4/CD8 positive TH cells in splenic T lymphocytes of CM-W group were increased compare to control group. These results suggest that CM-A and CM-W may be used in treatment of alopecia areata.