Abstract: Crosslinked quaternary ammonium anion exchange resins having a copolymer backbone containing a major amount of units derived from at least one non-polar aromatic monovinyl monomer and a minor amount of units derived from at least one polar functionally substituted comonomer, and characterized by improved physical stability, are prepared by an improved process, wherein the improvement comprises haloalkylating the aromatic nuclei of the copolymer backbone and aminolyzing the intermediate copolymer in the absence of added organic solvent.