In order to improve the stabilization and spinnability of polyacrylonitrile, a bifunctional comonomer containing both ester and amide groups was synthesized to prepare poly(acrylonitrile-co-3-aminocarbonyl-3-butenoic acid methyl ester) [P(AN-co-ABM)] copolymers used as the carbon fiber precursor instead of poly(acrylonitrile-acrylamide-methyl acrylate) [P(AN-AM-MA)] terpolymer. The differential scanning calorimetry and thermogravimetry results show that the stabilization of P(AN-co-ABM) have been remarkably improved by ABM compared with P(AN-AM-MA) terpolymer, such as lower initiation temperature, broadened exothermic peak and smaller activation energy. Moreover, the spinnability of P(AN-co-ABM) is also improved by ABM due to the lubrication of ester groups in ABM. This study clearly shows that P(AN-co-ABM) copolymer is a better material for use as a carbon fiber precursor than P(AN-AM-MA) terpolymer.A bifunctional comonomer containing both ester and amide groups was synthesized to prepare poly(acrylonitrile-co-3-aminocarbonyl-3-butenoic acid methyl ester) [P(AN-co-ABM)] copolymers used as the carbon fiber precursor instead of poly(acrylonitrile-acrylamide-methyl acrylate) terpolymer. The results show that the stabilization and spinnability of P(AN-co-ABM) copolymers have been significantly improved by the comonomer ABM.