Sweet potato (Ipomoea batatas (L.) Lam.) is an important food crop with great source of starch. Sweet potato starch has inferior properties like high swelling power, soft gel texture and low paste clarity. Peracetic acid is an environmentally friendly oxidizing reagent without harmful effects to human health. This research evaluated the feasibility of peracetic acid concentration (2, 4, 6, 8, 10 ppm) and starch slurry ratio (1:8, 1:10, 1:12, 1:14, 1:16 w/w) to functional characteristics of the oxidized sweet potato starch. Results showed that the highest swelling power (57.34%), solubility (2.68%) and peak viscosity (6264 cP) were obtained by peracetic acid 6 ppm and starch slurry ratio 1:12 w/w. Peracetic acid could be successfully applied as a powerful oxidizing agent in starch modification.