Various methods for modifying poly(vinyl alcohol) with cationic groups have been investigated using two cationic reagents and 10 cationic monomers. The cationic monomers of acrylamide and methacrylamide derivatives such as N-(1,1-dimethyl-dimethylaminopropyl) acrylamide (APA) and N-(dimethyl aminopropyl) methacrylamide (APM) and their quaternary ammonium salts (QAPA and QAPM) shown below have been found useful to produce cationic poly(vinyl alcohol)s by copolymerization and alcoholysis because of their much higher reactivity in copolymerization and because the amido linkage has good stability for alkaline alcoholysis.CH2 = C(H)-CONHC(CH3)(2)CH2CH2N(CH3)(2)[APA]CH2 = C(CH3)-CONHCH2CH2CH2N(CH3)(2)[APM]CH2 = C(H)-CONHC(CH3)(2)CH2CH2N+(CH3)(3)Cl-[QAPA]CH2 = C(CH3)-CONHCH2CH2CH2N+(CH3)(3)Cl-[QAPM]Modifications with dimethyl aminoethyl vinyl ether, 1-methyl vinyl imidazole and their quaternary ammonium salts have also been investigated and regarded as useful for the preparation of poly(vinyl alcohol)s having more stable cationic groups. The cationically modified poly(vinyl alcohol)s show specific functions such as high adsorption to fibrous pulp dispersed in water, formation of polyelectrolyte complex and emulsifying ability to make cationic emulsion. Partially hydrolysed poly(vinyl alcohol)s modified with QAPM have been found to show unusually high viscosity in aqueous solutions such as 2000 cP at 4 wt% and 20 degrees C.