This study was conducted to evaluate the efficacy of mulberry leaf mixed diet on larval growth of Protaetia brevitarsis. As a result of adding mulberry leaves to oak fermented sawdust, the survival rate of P. brevitarsis larvae were higher than those of the control when mass rearing larvae. When fed oak fermented sawdust with 5%, 10% and 20% of mulberry leaves, the cumulative proportion of larvae over 2.5g was 93.1% at 65 days, 95.6% at 55 days, and 93.9% at 55 days after rearing at 25±1℃, respectively. Also, heavy metals were not detected in larvae of P. brevitarsis fed on mulberry leaves.