The current study was carried out to investigate the effect of water salinity (5, 15, 25, and 35‰) on growth performance, survival, feed utilization, and body chemical composition of the Pacific white shrimp, Litopenaeus vannamei, juvenile in the water environment of Qaroun Lake. Juveniles of L. vannamei with initial body weight (2.77 ±0.12g) were acclimated to laboratory conditions for 14days before being randomly distributed into in eight circular fiberglass tanks with a volume of 1.5m³ for 80-days at a stocking density of 40 juveniles/tank. All tanks were provided with continuous aeration. Results revealed that survival (%) was within the range of 90–98.75%, recording insignificant differences. Results of growth performance parameters were the highest with shrimp reared in water salinity (5‰) compared to the other salinity percentages. The best FCR (lowest values) was recorded with shrimp reared in water salinity of 5‰. While shrimp reared in water salinity (35‰) showed the worst FCR. The lowest body protein content was recorded with shrimp reared in water salinity of both 5 and 15 ‰. The opposite trend was recorded for body ether extract. Based on the obtained results, the optimum growth rate of L. vannamei was obtained when reared in water salinity of 5‰ under experimental conditions which makes it suitable for cultivation in the water environment of Lake Qarun.