This study was aimed to investigate whether the bacterium Enterococcus hirae can be used as a probiotic for promoting the growth of the prawn, Macrobrachium rosenbergii post-larvae (PL). Artemia franciscana nauplii were enriched with E. hirae at five different serially diluted concentrations (10 -1 , 10 -3 , 10 -5 , 10 -7 and 10 -9 ). A 45 day feeding trial revealed that the survival, growth, concentrations of total protein, amino acid, carbohydrate and lipid, and activities of protease, amylase and lipase were significantly (P<0.05) increased in experimental PL, particularly at 1764×10 -7 , CFU. Further, the consortium of the gut microflora of un-enriched Artemia nauplii fed PL showed the presence of Escherichia coli, Klebsiella sp., Citrobacter sp., Acinetobacter sp., Streptococcus sp., Bacillus sp., Staphylococcus sp. and Pseduomonas sp. In E. hirae enriched Artemia nauplii fed PL showed the presence of Enterococcus sp., E. coli, Lactobacillus sp., Acinetobacter sp. and Staphylococcus sp. It was found that the pathogenic bacteria Klebsiella sp., Citrobacter sp., Streptococcus sp. and Pseduomonas sp. were competitively excluded by the colony establishment of Enterococcus sp. in experimental PL. Therefore, E. hirae can be used as a probiotic for promoting the sustainable culture of M. rosenbergii.