Radical particles are shown to appear under irradiation (hv greater than or equal to 2.8 eV) of H-ZSM-5 zeolites with adsorbed benzene. The particles appeared to be benzene cation-radical precursors over the zeolite. Heating resulted in irreversible destruction of the particles and emergence of a benzene cation-radical spectrum. The obtained radicals have no detectable hyperfine splittings on the protons, their spectrum remaining almost the same when deuterobenzene was used. The possible structure of the particles is discussed.