To modify the surface of inorganic fibers such as glass fiber (GF), alumina fiber (AlF), and carbon fiber (GF), we investigated the grafting of polymers by termination of living polymer cation with amino groups introduced onto the fiber surface. The introduction of amino and N-phenylamino groups onto GF and AlF were achieved by the treatment of fiber surface with gamma-aminopropyltrietoxysilane and N-phenyl-gamma-aminopropyltrimethoxysilane, respectively. The introduction of amino groups onto CF was performed by the reduction of nitrated CE These amino groups on inorganic fiber surface readily reacted with living poly(isobutyl vinyl ether) (poly(IBVE)) cation, and poly(IBVE) with controlled molecular weight and narrow molecular weight distribution was grafted onto the surface. By the termination of living poly(2-methyl-2-oxazoline) (poly(MeOZO)) cation with amino groups on inorganic fiber, poly(MeOZO) was also grafted onto the surface. The mole number of grafted polymer chain on inorganic fiber surface decreased with increasing molecular weight of the living polymer, because the steric hindrance of inorganic fiber surface increases with increasing molecular weight of the living polymer. The wettability of the inorganic fiber surface readily controlled by grafting of polymers onto the surface.