AbstractCorncob, an underutilized agricultural byproduct, was used as the raw material to make a dry-strength additive for paper. Corncob was ground into 80, 100, 150, and 200 mesh powder. The powder was treated with sodium chlorite to remove lignin, and the resulting holocellulose was modified with hydrogen peroxide. The influences of oxidation time, concentration of hydrogen peroxide, dosage of paper strength agent, and the dosage of aluminum sulfate on the paper properties were studied. The results indicate that the oxidized corncobs holocellulose can improve the tensile index, burst index, and folding endurance of paper. Compared with control paper, when the concentration of hydrogen peroxide was 0.9%, the tensile index, burst index, and folding endurance were increased by 24.2%, 14.1%, and 463.8%, respectively. The particle size of raw material, dosage of strengthening agent or aluminum sulfate greatly influences paper properties. Scanning electron microscopy (SEM) analysis showed that the combination between the fibers was improved after adding the strengthening agent, thus improving the strength of the paper. The results can provide a new method for value-added use of corncob.