Probiotics supplementation aids in improving water quality, preventing disease and enhancing production in aquaculture. In the present study, Bacillus subtilis and Streptomyces parvulus were added with 10⁵ CFU/ml every five days to evaluate the effect of them on water quality of white leg shrimp (Litopenaeus vannamei) culturing. Four treatments in triplicated namely controlled treatment (without supplementation of bacteria), Bacillus subtilis, Streptomyces parvulus and the mixture treatment (Bacillus subtilis and Streptomyces parvulus, 1:1 ratio) was conducted in 120L tanks with stocking density 0.5 PL₁₅/L. After 60 days of culture, result showed that water parameters including temperature, pH, DO, and alkalinity were suitable for the growth of white leg shrimp. Parameters such as TAN, COD, TSS, and NO₂ varied among treatments and tended to increase towards the end of the experiment. Although these parameters were rather higher, supplied bacterial treatments had better water quality than controlled treatment. Density of Vibrio in the control (4.27×103±404 CFU/mL) was significantly higher (p0.05)with mixture treatment (62.67±4.16), and was significantly different (pBacillus subtilis and Streptomyces parvulus) and their mixture were considered to be the environmentally friendly and effective method on improving water quality, preventing disease pathogen, enhancing survival rate and growth performance of white leg shrimp (Litopenaeus vannamei) compared to the control.