SynopsisT h e solution polymerization of vinyl acetate w a s curried out in several solvents a t 0 to 100cC, using 2,2'-azobisisobutyronitrile as initiator. For the resulting poly(viny1 alcohol) (PVA), iodinecoloration, 1.2-glycol structure and tacticity were observed. The pentad tacticity of PVA was estimated from its methine carbon spectra by means of '"C-FTNMIi spectrometer. Iodine-coloration ahility of PVA v M d markedly with the type of polymerization solvent and decreased in the following order: phenol > aq. phenol > methyl alcohol ethyl acetate > IIMSO, ethylene carboriiite. T h e syndiotactic fraction in PVA also decreased with polynierimtion solvent in the .same order (ts that of iodine coloration, while 1,2-glycol content of PVA was not almost affected by polymerization solvent except for phenol and aq. phenol. In solution polymerization performed, effect of polymerization temperature on tacticity was less than that of solvent. 15. F.