An artificial hair having a physiologically active surface which is formed by a such manner that protein (collagen) molecules are bonded chemically to the graft-polymerized chains introduced onto the surface of the artificial hair. When the artificial hair is implanted into a human body skin, the collagen layer 11 fixed to the surface of the artificial hair having a root part 12 is integrally assimilated and bonded to collagens in the epidermis 4, the corium layer 5, the subcutaneous tissue 6 and the galea 7, whereby the artificial hair can be firmly fixed. Thus, this artificial hair exhibits a low infection rate, a high success rate and cannot be accompanied by down-growth phenomenon.