Striped catfish (or tra catfish) (Pangasianodon hypophthalmus) is one of the important species in the aquaculture of Vietnam. Its production was 1.53 million tons in 2021 (VASEP 2022). The saline water intrusion to the culture area due to climate change could affect the farming practices. This study aims to understand the osmotic and ionic regulation, feed intake and growth performance, feed evacuated through the stomach and dry matter and protein digestibility of fish exposed to different salinities. The tolerance of fish (16.3 ± 1.8 g) acclimated to different salinities by a stepwise increase in 1 ppt salinity per day was conducted at the laboratory conditions with 8 treatments from 1 to 21 ppt with the interval of 3 ppt. The mortality occurred when the water reached a salinity of 18 ppt. An isomotic point level was found at 9 ppt (270 mOsmol kg-1 ). In high salinity, the animals failed in their ionic regulatory capacity. The growth of fish in different salinities was conducted in the fiberglass tanks of 500 L volume with triplicate for 60 days. Salinities were from freshwater to higher than the iso-osmotic point including 0 (control), 3, 6, 9, and 12 ppt. The body mass and specific growth rate of fish reared at 9 ppt was significantly higher in comparison with those in other treatments. The survival rate of the fish reared at 12 ppt was lowest (96.0 ± 2.5%). Fish reared in 12 ppt consumed more feed if compared to those in freshwater and 9 ppt. The dry matter and protein digestibility were not significantly different among the treatments from freshwater to 9 ppt, but significantly lower at 12 ppt. This study proves that striped catfish can be grown in brackish water up to 9 ppt