This study was performed to evaluate the quality characteristics of yanggeng prepared with different amounts of Rehmanniae radix Preparata (RRP) concentrate. Moisture, acidity, soluble solids, and reducing sugar contents of the control were the lowest, followed in order by the 3%, 6%, and 9% RRP addition. The pH of 9% RRP added yanggeng was the lowest, followed in order by the 6% and 3% additions. The lightness value of the Hunter color system decreased based on the amount of RRP concentrate added to yanggeng. In the texture analysis, the hardness and cohesiveness of the 9% RRP added yanggeng were the highest among the treatments. Total phenol content was the highest in 9% RRP added yanggeng. Antioxidant activities such as DPPH radical scavenging activity and hydroxyl radical scavenging activity, were the highest in the 9% RRP added yanggeng. In the sensory evaluation for yanggeng, the sensory scores for overall preference and texture were the highest in the 6% RRP added yanggeng The result was suggested that the optimum amount of RRP concentrate to add to yanggeng was 6%.