Insoluble polystrenes containing formamide and acetamide moieties were prepared by free radical terpolymerization of the corresponding vinyl monomers, styrene, and divinylbenzene. These polymers served as phase transfer catalysts for the reaction of n-octyl bromide with potassium thiocyanate in toluene–water system. The activity of these catalysts was affected by some factors such as stirring speed particle size, and degree of crosslinking. The activity also depended strongly on the structure of active site, copolymer composition, and spacer length which cause the difference in the adsorption of potassium ion and in the microenvironment around the active site. Furthermore, nylon-66 was found to display the activity for phase transfer reactions, and the activity was remarkably increased by replacing the amide hydrogen with an alkyl group.