The purpose of this study was to investigate the quality characteristics of Sulgidduk prepared by adding the optimal amount of apple powder. Five different mixture ratios of apple powder to rice flour were prepared (0, 4, 8, 12, and 16%). After being stored for 3 days, the mixtures of apple powder and rice flour were measured to determine moisture content, color values, sensory qualities, and the mechanical texture characteristics of Sulgidduk. Moisture content of Sulgidduk with added apple powder ranged from 36% to 39% and but decreased with significantly with added apple powder. The L-color value decreased, whereas both the a-and b-values increased as apple powder was added. Thus, apple peel likely affected the Sulgidduk color value. The pH of Sulgidduk decreased with the addition of apple powder, whereas sugar level increased as apple powder was added. In the mechanical evaluation of apple Sulgidduk, hardness was significantly higher during the 3 days of storage with increasing amounts of added apple powder. Cohesiveness increased significantly during the storage period with the addition of apple powder,-; however, it began to decreased after 3 days. Springiness increased significantly with the addition of apple powder. Both adhesiveness and chewiness of Sulgidduk increased with added apple powder. Sensory quality characteristics such as color, taste, flavor, and moistness were improved with increasing amounts of added apple powder. However, the sensory quality of Sulgidduk decreased when the ratio of apple powder to rice flour was greater than 25%. Consequently, a mixture of 15~20% apple powder to rice flour was the best formula for improving Sulgidduk in terms of sensory quality.