Anionic polymerizations of 2-vinylbenzoxazole (1) and 2-isopropenylbenzoxazole (2) mere carried out in THF at -78 degrees C with (diphenylmethyl)potassium and (1,1-diphenyl-3-methylpentyl)lithium. The poly(1)s having broad molecular weight distributions (M(w)/M(n) > 1.5) were always obtained in rather low yields both after 1 h of polymerization and even after 24 h. On the other hand, the polymerization of 2 proceeded quantitatively with each initiator within 1 h and the resulting poly(a)s possessed the predicted molecular weights and narrow molecular weight distributions (M(w)/M(n) < 1.1). The persistency of the propagating carbanion of poly(2) was demonstrated by a quantitative initiation efficiency in the postpolymerization of 2. These results strongly indicate that the anionic polymerization of 2 affords a stable living polymer. Novel block copolymers, poly(2-b-tert-butyl methacrylate), poly(2-b-tert-butyl methacrylate-b-2), and poly(2-b-styrene-b-2), were successfully synthesized by the sequential block copolymerization of 2 and comonomers.