A strain, Streptomyces sp. A1 isolated from shrimp pond sediments has been identified as an aquaculture probiotic antagonistic to pathogenic Vibrio harveyi V7. In the present study, the different carbon and nitrogen sources in a mineral base of SGB were investigated for the biomass production and antagonistic activity to Vibrio harveyi V7 of Streptomyces sp. A1. The results show that optimal carbon and nitrogen sources for biomass production and antagonistic activity to Vibrio harveyi V7 of Streptomyces sp. A1 is starch and casein, respectively. The optimal concentrations of starch and casein are 13g/L and 0.6g/L respectively.