Abstract: Disclosed is a process for preparing a water-soluble bead polymer by dispersing drops of an aqueous solution of water-soluble vinyl monomer in a dispersing medium in the presence of a dispersion stabilizer, and polymerizing the monomer by using monomer selected from the following A and B(a) a compound of the general formula I ##STR1## wherein R.sup.1 is hydrogen or methyl, R.sup.2 and R.sup.3 may be the same or different and each is linear or branched alkyl of from 1 to 4 carbon atoms, R.sup.4 is hydrogen, linear or branched alkyl of from 1 to 8 carbon atoms, hydroxy alkyl of from 1 to 4 carbon atoms, or benzyl, Y is alkylene or hydroxyalkylene each of from 2 to 4 carbon atoms, and X.sup.- is an anion, or(B) a mixture of the compound of the formula I and a water-soluble vinyl monomer copolymerizable with the compound (I), and a cellulose ester or a cellulose ether insoluble in water but soluble in the dispersing medium is used as the dispersion stabilizer.