Cationic polydextrose was prepared with a quaternary ammonium salt Q-188,3-chloro-2-hydroxypropyl-trimethyl ammonium chloride as cationic etherifying agent, polydextrose, fructooligosaccharides and polydextrose galacto-oligosaccharid-esin soluble dietary fiber as raw material, ethanol as solvent,under alkaline conditions. Degree of cationic substitution was determined with semi-micro Kjeldahl method, and their structures were characterized by FT-IR and13CNMR. Under the support of the known literature, extra...