Abstract: Cross-linked octenyl succinate rice starch ( CLOSRS) was prepared using rice starch as a material, sodium trimetaphosphate as a cross-linking agent, and octenyl succinic anhydride ( OSA) as a esterifying agent.Results showed that the optimal conditions for preparing CLOSRS were as follows: reaction temperature 85 ℃, reaction time 2.5 h, pH value 9.5 and OSA amount of 4.0%.The degree of substitution ( DS) of CLOSRS under the optimal conditions could be 0.0198.After rice starch was cross-linked and esterificated, physicochemical properties and pasting property were improved.The solubility of rice starch increased from 2.73% to 15.88%, and the light transmittance rised from 7.57% to 14.73%. And the increase in freeze-thaw stability was also caused. After cross-linking and esterification, moreover, the peak viscosity was increased from 2246 cp to 5326 cp, but the setback were reduced from 1276 cp to 273 cp, and peak temperature was from 82.45 ℃ to 76.32 ℃.