Two trials were conducted to determine the best stocking density and the optimum of water change period on growth performance and feed utilization of rabbitfish  juvenile (Initial body weight 0.948 g ± 0.124). Stocking density was tested in the first trial, which consisted of four treatments. The fish were stocked at 10 fish/m³ and 20, 30 and 40fish/ m³ in four treatments respectively. The results showed significant differences between the treatments and cleared that, stocking density 10 and 20 fish / m³ were the better than 30 and 40 fish / m³ in growth and feed utilization parameters. The results affirmed that, an increase of fish number over 20 fish/ m³ lead to a decrease of growth and feed utilization parameters. The second trial designed to evaluate different four periods of the water exchange at rate 50 % of the water volume. The water was exchanged every day, every two days, every three days and every four days in the first, second, third and fourth treatments respectively. The results revealed significant differences between the treatments and cleared that, the best total weight gain and feed conversion ratio were achieved with the third treatment (water exchanged every three days) and the water quality was within the acceptable limits for fish growth in all treatments.