Abstract: 4-vinyl benzyl 4-oxo-4-((4-(phenylamino)phenyl)amino)butanoate (VPB) were designed and synthesized, and then polymer nanosheets were successfully prepared by self-assembly and polymerization of the VPB. Structures of the VPB and the polymer were characterized by HNMR spectroscopy and infrared spectroscopy. Self-assembly of the VPB and the polymers were investigated by transmission electron micrography and X-ray analysis. The results indicate that VPB can self-assemble into two-dimensional nanosheets in the mixed solution of toluene and acetone, and morever, VPB can be copolymerized with N-butyl maleimide to form a polymer nanosheet with a size of several micrometers and thickness of 2 nanometers. It has been demonstrated that the combination of self-assembly and free radical polymerization is a convenient and efficient approach for the preparation of polymer nanosheets.