This article reports a new ‘‘one-step’’ synthesis of graft polymers based on the radical/cationic transformation polymerization. Using the synthetic method proposed, a graft polymer (PVAc-g-[P(AN-r-BVE)b-PCHO]) consisting of a partly hydrolyzed poly(vinyl acetate) (PVAc-OH) backbone and block polymer grafts of acrylonitrile/n-butyl vinyl ether random copolymer (P(AN-r-BVE)) and poly(cyclohexene oxide) (PCHO) was synthesized in situ by radical/cationic transformation polymerization of a mixture of AN/ BVE/CHO in the presence of PVAc-OH. The graft polymer, PVAc-g-[P(AN-r-BVE)-b-PCHO], was fully characterized by 1 H NMR, IR, gel permeation chromatography and differential scanning calorimetry. The graft polymer, PVAc-g-[P(AN-r-BVE)-b-PCHO], was hydrolyzed with NaOH to form a poly(vinyl alcohol)based amphiphilic graft polymer, PVA-g-[P(AN-r-BVE)-b-PCHO]. The aggregation behavior of the amphiphilic graft polymer was investigated briefly by atomic force microscopy and dynamic light scattering measurements.