Aquaculture fisheries production plays an important role in food and nutritional security. Ensuring production while decreasing the cost for feeds through alternative feeds will be beneficial. Thus, this study was conducted to evaluate the growth performance of orange spotted spinefoot rabbitfish (Siganus guttatus) fed with mulberry leaves. The study up in 1x1x1.5m hapa net between 10m distance experimental design using four (4) treatments specifically control treatment T0 - commercial feeds, Treatment 1 T1 - 75% commercial feeds: 25% mulberry leaf, T2 - 50% commercial feeds: 50% mulberry leaf, T3 - 25% commercial feeds: 75% mulberry leaf. To test the significant difference among the treatments, One way ANOVA with Duncan Multiple Range Test was used. It was found out that there was a significant difference in the growth increment of S. guttatus among the treatments in length, width and weight. It was concluded that T3 is effective for the growth of S. guttatus as cultured in Brackish water environment and can be embedded in its management program.