Radicals induced by gamma-irradiation in sucrose, in the solid state at different temperatures and in aqueous solution, have been studied by the spin-trapping method. Electron spin resonance (ESR) combined with high performance liquid chromatography (HPLC) then spectra analysis with a simulation program (VOYONS), revealed seven main radical species. Their nitrogen and hydrogen splitting constants were compared with those obtained from fructose and glucose units. Assignments of chemical structures are discussed for three radical species.