Poly(p-phenylenesulfide) (PPS) is efficiently and conveniently produced by a cationic and oxidative polymerization. Diphenyldisulfide is polymerized to PPS through one electron transfer at room temperature. The polymer is isolated as a white powder whose 1,4-structure is confirmed by IR. Phenylbis(phenylthio)sulfonium ion acts as an active species which is formed by oxidation of the S-S bond of diphenyldisulfide, and electrophilically substitutes on the phenyl ring. This polymerization is applicable to the polymerization of alkyl-substituted diphenyldisulfides to give PPSs, such as poly(2-methylphenylenesulfide) and poly(3,5-dimethylphenylene-sulfide).