The preparation of spacer-modified polystyrene supports, ω-bromoalkylated polystyrenes, was performed by the one-pot reaction of microporous, 1 or 2 mol% crosslinked polystyrene resins with ω-bromoalkenes using CF 3SO 3H as catalyst. The bromoalkylation of the crosslinked resins could be achieved over the degree of functionalization of 0.13–0.42 by changing concentrations of ω-bromoalkenes and CF 3SO 3H. The bromoalkylated product obtained from a soluble polystyrene and 11-bromo-1-undecene was analyzed by gel permeation chromatography and 1H NMR spectroscopy, which indicated para-alkylation of the phenyl groups of the polystyrene. The phase-transfer catalytic activity of immobilized phosphonium salts derived from the bromoundecylated polymer supports was higher than that of the corresponding salts derived from chloromethylated polystyrene supports. The effect of the crosslinking level, the degree of functionalization, and the particle size of the spacer-modified catalysts on the activity was also studied.