This study aimed to compare the ability of glutaric and succinic anhydrides for surface modification of cellulose using the green and solvent-free grafting method. The conductometric titration results showed that both anhydrides could successfully introduce carboxylate functional groups on the cellulose surface with 1.5±0.2 and 3.5±0.2 mmol carboxylic acid/g cellulose for glutaric and succinic anhydride, respectively. The FTIR spectra demonstrated the presence of carboxyl functional groups on all samples, and the zeta potential results confirmed increasing surface charge from −10.9±0.6 to −23.03±1.7 mV for grafting with glutaric and succinic anhydride, respectively. SEM showed all samples had fibrous structure; however, fiber diameter and length decreased after the grafting process. DSC profiles showed that grafting could slightly change the apex temperature of treatments while not significantly changing the transition phases. The findings of this work suggest that glutaric anhydride can be used as a promising esterification agent in a greener, solvent-free, and catalyst-free grafting process.