The state of macromolecular aggregation of hydrolyzed product of graft copolymers of acrylonitrile onto starches prepared by γ-ray and Ce(Ⅳ) initiator respectively was investigated with elemental analysis, IR spectrum, X-ray diffraction and SEM. The results indicate that in a spite of different initiating, by "bridging" of graft side chains there are the various sizes of cavities and random crosslinking in the state of aggragation, and the macromolecular chains include -COONa and -CO-NH,2, groups, which show stronger infrared absorption 1400 cm,-1, and 1652 cm,-1, bands respectively. The structure characterization is associated with water retention.