A feeding trial was designed to study the fish farming system – high density recirculating aquaculture system (HD-RAS) and developed to achieve extreme high densities of fish culture in a designated area and controlled environment. The study used the hybrid grouper - Epinephelus fuscoguttatus (♀) × Epinephelus lanceolatus (♂) as an experimental fish model to test the performance of the high density recirculating aquaculture system, and analyzed the growth dynamics of the groupers in the HD-RAS. In the experiment, growth indexes and main water quality indicators were analyzed to determine farming system. The temperature of water in the HD-RAS was between 26 to 29°C, the salinity was 25 to 30 ‰, and the DO was equal to or greater than 8 mg/L. The concentrations of ammoniacal nitrogen and nitrite were 0.3 to 0.9 mg/ L and 0.1 to 0.25 mg/ L respectively. The whole test lasted for 250 days and was divided into three successive stages. Phase 1 (Day 1 to 87), the density of grouper culture increased from 13.82 kg/ m3 to 28.89 kg/ m3, the survival rate was 95.28%, the average weight increased from (150 ±18) g to (329±42) g, and the SGR was 0.90±0.06. Phase 2 (the following 106 days after Phase 1), the culture density increased from 28.89 kg/ m3 to 53.36 kg/ m3, the survival rate was 90.44%, the average weight increased from (329±42) g to (672±66 )g, and the SGR was 0.67±0.02. Phase 3 (the last 57 days), the culture density continued to increase from 46.98 kg/ m3 to 69.50 kg/ m3, the survival rate was 98.6%, the average weight increased from (676±52) g to (1 014±75) g, and the SGR was 0.71±0.02. In the whole 250-day cultivation period the average SGR was 0.76±0.02, the total survival rate was 84.9%, the average feed conversion ratio (FCR) was 1.04 and economical input/output ratio was 1:2.02. In summary, the study provided strong evidences for the possibility to culturing E. fuscoguttatus (♀) × E. lanceolatu (♂) at large scale and extremely high density using the novel HD-RAS.