Octenylsuccinated corn starches prepared by reaction of corn starch with 1octenylsuccinic anhydride(OSAn) and their degree of substitution (DS), reaction efficiency(RE), residual octenylsuccinic acid (OSA), and physicochemical properties were compared with those of the native corn starch. DS increased with increase of OSAn and RE was much nearly the same regardless of increase of OSAn. The content of residual OSA was significantly lower than that of regulation of food additives. And as washing frequency of dispersion of the reactant was increased, the content of residual OSA of octenylsuccinated starch was decreased. Rapid Visco-Analyzer initial pasting temperature and setback of octenylsuccinated starches decreased whereas peak viscosity and breakdown increased. When DS of octenylsuccinated starches increased, temperature of initial gelatinization of octenylsuccinated starches drastically decreased. The octenylsuccinated starches also formed clearer pastes. The solubility was much nearly the same regardless of increase of DS at 70℃ but the swelling power increased about 1.2-1.7 times higher than that of native corn starch at 70℃. The water binding capacity of octenylsuccinated starches also decreased.