The purpose of this study was to investigate the improvement effect of biomarkers through the supply of natural diet in the juvenile hybrid abalone (Haliotis discus discus♀*H. madaka♂). For the study, the shell length of about 17 mm and the total weight of 0.83 g were used. The feeding conditions were set as the natural diet group (dried laver) and the formulated diet group, and the experiment duration was 16 weeks. The survival rate was about 14% higher in the natural diet group than the formulated diet group, and growth was also faster in the natural diet group. Shell malformation rate was lower in the natural diet group (7.5%) than the formulated diet group (21.5%). In the biochemical composition, except for carbohydrates, both experimental groups showed similar values. The degeneration of epithelial cells in the hepatopancreatic tubule was lower in the natural diet group than the formulated diet group, and the activity of basophilic cell was higher in the natural diet group. These results indicate that it is worth considering the supply of natural diet for the breeding of juvenile hybrid abalone and the improvement of the quality of the formulated diet (H. discus discus♀*H. madaka♂).