The integration of freshwater prawn (Macrobrachium rosenbergii) and red seaweed (Gracilaria tenuistipitata) was conducted consisting of five treatments and run in triplicate. Prawn monoculture fed 100% commercial feed ration as a control, other four treatments prawn were integrated with red seaweed (1.5 kg/m³) and received 80%, 60%, 40% and 20% feeding rations. Prawn juvenile (0.53±0.04 g) were stocked in the 250-L tanks with density of 100 ind./m³ and at salinity of 5 g/L for 90 days. Results showed that the concentrations of TAN and NO^-₂ in the integrated tanks were lower than that in the monoculture. Survival and growth rates of prawn in the integrated treatments received 40% feed ration were superior to those in the control and other treatments, and feed conversion ratio could be reduced up to 66.7% compared with the control group. Additionally, ash, protein and lipid contents of prawn meat in co-culture were better or similar to that of the control. It can be suggested that applying 40% commercial feed ration in the integration of M. rosenbergii and G. tenuistipitata gave optimal growth performance, improved survival and feed efficiency, as well as maintain better water quality in prawn culture.