This paper reports the chemoenzymatic synthesis of an amylose-grafted cellulose. A maltoheptaose was chemically introduced to the amine-functionalized cellulose by reductive amination to produce the maltoheptaose-grafted cellulose. Then, the phosphorylase-catalyzed enzymatic polymerization of glucose 1-phosphate from the graft-chain ends on the cellulose derivative was performed, giving the amylose-grafted cellulose. The obtained material is shown to form gels and films. The dry and wet cycles of the materials were repeated.