L. Vannamei is one of the most important species of farmed shrimp that spread quickly across farming areas. Since any changes in environmental factors will always threaten their health, so by measuring of blood parameters, the effects of salinity fluctuations can be examined on growth and health indicators. To evaluate each of variable salinity in this study, four separate experimental groups each with three treatments with 3 replications were used. According to the results, any stress arising from increase or decrease in salinity rate may be associated with abnormalities in the immune system, so that its activity in salinity of 15 and 45 g/L compared to 30 grams of salt per liter was associated with a significant decrease in the values of heamocyte cells and total protein in blood plasma (P <0.05). It can be concluded that the most appropriate salinity degree in L. Vannamei growth is 30 grams per liter.