The aim of this study was to determine the optimum amount of apricot seed powder to add to rice flour in oder to prepare Sulgidduk (traditional rice cakes). As the apricot seed powder level of the Sulgidduk increased, the moisture contents of the samples decreased (40.30~43.46%), and the color of L- and a-values also decreased, while the b-value increased. According to instrumental test results, hardness, springiness, gumminess, chewiness and adhesiveness were all highest in the 0% apricot seed powder sample. The cohesiveness of samples did not show a conclusive relationship with the level of apricot seed powder present. In sensory evaluation results, the 3% and 6% samples received high overall acceptability scores. In conclusion, based on both sensory and instrumental testing, the optimal Sulgidduk mixture consisted of 3~6% apricot seed powder added to rice flour.