Acrylonitrile (An) was copolymerized with N-methacryloyl-DL-$alpha$-valine (MAV) in order to increase moisture regain and impart an affinity for acid dyes. MAV was prepared by Schotten-Baumann reaction of DL-$alpha$-valine with methacryloyl chloride. The identification of MAV was conformed by IR spectrum, melting point and elemental analysis. Monomer reactivity ratios were calculated and inherent viscosity, tensile strength, moisture regain, dye absorption for acid dye, and decomposition temperatures of copolymers were investigated. The moisture regain, dye absorption for acid dye, inherent viscosity were investigated. The moisture regain, dye absorption for acid dye, inherent viscosity were increased, but tensile strength, decomposition temperature were decreased in proportion to the mole % of MAV.