The aim of this study was to determine the optimum amount of perilla leaves to add to rice flour in the preparation of Sulgidduk(perilla leaf rice cake). By increasing the perilla leaf level in the formulation, the moisture contents of samples increased ($42.06{sim}48.17%$), and their L-values decreased. The control and 16% perilla leaf Sulgidduk had higher a-values than the other samples, and the 8% perilla leaf Sulgidduk had the highest b-value. According to the mechanical evaluation results, hardness, gumminess, chewiness, and fracture decreased with increasing amounts of added perilla leaf. However, the springiness of samples during storage did not differ significantly according to the level of added perilla leaves. From the sensory evaluation results, the 12% perilla leaf sample received the highest overall-acceptability scores. In conclusion, according to its sensory and mechanical qualities, the optimal Sulgidduk formulation consisted of 12% perilla leaves added to rice flour.