An 8-week trial was conducted to investigate the effects of dietary protein levels which were 20.61, 30.52, 40.43 and 50.34% (named CP20, CP30, CP40 and CP50 respectively) on the growth, survival, body composition of the white shrimp, Litopenaeus vannamei, at three ambient salinities which were 2, 22 and 32 respectively. The results showed that ambient salinity had significant effects on shrimp growth, survival, conditional factor(CF) and body ash, while no significant differences were observed in the hepatosomatic index (HSI), body crude protein, lipid and moisture. Shrimps at 22 were the highest in all the parameters followed by these at 32 and 2. Weight gain, specific growth rate for both weight and body length of shrimps at 32 and 22 were significantly higher than those at 2, while no differences were found in shrimps at 32 and 22. Dietary protein levels only significantly affected the growth performance, body crude protein, CF and HSI of the shrimps. Weight gain and the body crude protein content of shrimps increased with the increasing of dietary protein level, and shrimps fed with CP20 showed significant lower growth performance and body crude protein. CF and HSI increased firstly with the dietary protein levels increasing to CP40 firstly, and then decreased slightly when fed with CP50. Dietary protein levels had no effect on the survival shrimp at all the ambient salinities. Ambient salinity and dietary protein level only had significant interaction on the body ash content, while no significant interaction effects were observed in other parameters. Tubules of shrimp fed with CP30 and CP40 had the normal structure, though CP40 increased the number of R cells. Tubules of shrimps fed with CP20 had relatively fewer R cells and arranged incompactly. And the basal membranes of partial tubules were in disrepair. While tubules of shrimps fed with CP50 compactly arranged with much ambiguous materials in B cells. The results indicated that though the growth performance and conditional factor could be increased by increasing dietary protein level, low survival rate at low salinity did not enhanced. And improper content of dietary protein, especially extremely lower dietary protein, would results in pathological changes of the hepatopancreans’ histological structure.