Living nature of the cationic polymerization of t-butyl vinyl ether(t-BVE), carried out at -78$^{circ}C$ in a mixed solvent of toluene and diethyl ether using iodine as initiator has been investigated. The results showing attainment of 100% conversion and a linear dependence of the number average molar mass on % conversion strongly suggests the living nature of the polymerization in a limited range of iodine concentration. It is concluded that the living nature of the polymerization is ascribable to the stability of polarized C-I terminal of adduct, which is formed by the reaction of the monomer with iodine and activated by the pulling action of zinc iodide, which allows the insertion of monomer in both initiation and propagation in cationic nature. However, it is believed that this growing terminal is stable enough to depress the chain breaking process, such as chain transfer or termination. Non-living characteristics appearing at higher temperatures as well as higher iodine concentration was discussed in terms of the equilibrium established between polarized C-I terminal and dissociated carbocationic propagating species where chain breaking process operates. It was also found that highly isotactic poly(vinylalcohol) (PVA) containing more than 70% meso content is obtainable via hydrolysis of corresponding p(t-BVE).