The influence of probiotics containing Bacillus sp (B2) and Bacillus amiloliquefaciens (B41) on water quality and white shrimp (Litopenaeus vannamei) performance cultured in tanks were studied. The experiment included two bacterial treatments and one control treatment (without Bacillus). Each treatment was in triplicate. All treatments were carried out in composite tanks with a stocking density of 50 ind./100L. Bacterial density was 10⁶ CFU/mL. The water quality in the different treatments by monitoring temperature, pH, DO, COD, TSS, TAN and total alkalinity were compared and evaluated. Water samples were analyzed before the bacteria were added and then sampled every 5 days until the end of the experiment (60 days). Sample collection and analysis was performed according to standard methods (APHA, 1995). Through out the experiment, we found that the temperature, pH, total alkalinity remained stable and suitable for most of aquatic animal. However, factors such as DO, COD, TSS, and TAN varied between treatments and tended to increase towards the end of the experiment. They were still suitable for shrimp farming. The density of Vibrio in additional bacterial treatments were lower than in  the control. The survival rate of shrimp in treatments B2 (70.0 ± 5.3%) and B41 treatments (86.7 ± 3.1%) were significantly higher (p< 0.05) than compared with those in the controls treatments (65.3 ± 3.1%)