The experiment on using formulated feeds for clown knife fish culture was conducted in six 20 m2 hapas (10 m x 2 m x 1 m) setting up in the 5.000 m2 earthen pond. Fish with the initial weight of 4.0 g were stocked at 8 fingerlings/m2. Fish were fed formulated feeds which were met protein and lipid requirements of fish at four levels of crude protein 42.5%, 38.6%, 33.6%, and 33.2% at the same lipid level at 9% for different growth stages of fish (Table 1). Fish was harvest at 238 days after stocking. In the control treatment, fish were fed by marine trash fish. Each treatment was replicated 3 times. The survival rate of fish feeding formulated feeds (81.6 ± 3.22%) was not significantly different with the control (76.7 ± 3.05) (p>0,05). Final mean weight (473,3±4,93 g and 489,3±5,16 g), daily weight gain (1,97±0,02 g/day and 2,04 ± 0,02 g/day) and yields (3,16±0,03 kg/m2 and 2,92±0,08 kg/m2) in the treatment using formulated feeds and the control, respectively were not significantly different (p>0.05). The feed cost per kg wet weight gain of fish from the formulated feed treatment (27,000 VND) was significantly lower than in the control (33,900 VND) (p