Abstract: To prepare corn resistant starch by pullulanase, and establish digestion kinetic model compared with corn starch.Digestion of resistant starch through different time was investigated by X- ray diffraction, differential scanning calorimetry, Fourier transform infrared.The results showed that corn starch was almost hydrolyzed in 2h, hydrolysis rate constant was 2.32h - 1 , higher than resistant starch ( 1.13h - 1 ) .Both crystallinity and enthalpy were increased, which showed that proceed mainly was hydrolysis kinetic.After 2h, crystallinity decreased but showed a disordered change process, amylose was rearrangement and linked by hydrogen bond, the formed polymer can resist amylase hydrolysis.The digestion showed a competition between the kinetics of enzyme hydrolysis and the kinetics of amylose retrogradation.