The effect of different salinity levels (15, 35, 50 ppt) and Freshwater on biochemical parameters and intestinal tissue of Lates calcarifer was surveyed for 30 days. This experiment in a completely randomized design with 4 different treatments Freshwater and salinity levels (15, 35, 50 ppt) and treated with 3 replicates and 15 fishes (initial weight 32gr) were used for each repetition. In this study some blood biochemical parameters (Sodium, Potassium, Chloride, Osmolality) was measured at the end of the experiment. The analysis results of blood biochemical parameters showed no significant differences between the treatments (P>0.05). This study also covers intestine histology of Lates calcarifer in 4 treatments was investigated and the results showed that the digestive system has normal villi and enterocyte and there was no significant difference in the location of the cell nucleus in the various histological slides. The images from different treatments were observed no histological lesions. The structure of mucous layers, muscular, serous and intestinal mucosa cells was normal and did not show significant differences. No significant difference in the results show that this fish is a species resistant to salinity environments hyperhaline tolerated.