Abstract: Retrograded starch has the positive influence on physiology. The retrograded potato starch dealed with oxalic acid was used as seeds to promote the retrogradation of corn starch. The retrogradation ratio was raised from 7.37% to 11.46%. All of the potato starch showed typical B type diffraction peaks after deposed by oxalic acid.It seemed that acid treatment made the morphology of starch more regularly.The potato amylose grew quickly in the solution of maize starch and showed obvious B type diffraction peaks,with the regular morphology.The low branching corn starch molecules in solution moved quickly to the seed of potato amylose and grew rapidly. The retrogradation ratio was enhanced and the morphology was similar to potato amylose. The findings in the paper provided a new way to control retrogradation of corn starch.