Cholesterol-based amphiphilic monomer, 1-ethenyl-3-(8-(cholest-5-en-3β-yloxy)-3,6-dioxaoctyl)-2-pyrrolidone(ECDP) and its monomeric and polymeric vesicles were synthesised, and the vesicle properties and structure were investigated. ECDP formed monomeric vesicles in water by sonication and injection of organic solution into water at 60℃. Polymeric ECDP vesicles were prepared by polymerization of monomeric ECDP vesicles in water with water-soluble initiator. The polymerization through NVP moieties of ECDP vesicles were confirmed by $^1H$-NMR, IR and $^{13}C$-NMR. The vesicles were observed in the electron microscope and confirmed by the entrapment of radiolabeled sucrose. The polymeric ECDP vesicles had more enhanced long-term stability than the monomeric vesicles. There was no change observed on the polymeric ECDP vesicles solution for several weeks. And polymeric ECDP vesicles showed more stability to dilute ethanol and saturated tannic acid addition than the monomeric ECDP vesicles.
