In this paper, the serum osmosis, serum ions concentration and Na⁺/K⁺-ATPase activity in branchial epithelium of were investigated in a ambient of salinity, alkalinity and orthogonal experiment. The results showed that osmolarity in serum and serum ions concentration(Na⁺, K⁺, Cl^{)were elevated significantly with the rising salinities(8,10,12,14g/L). The gill Na+/K+-ATPase activity increased in the beginning and decreased subsequently, Na+/K+-ATPase activitywas positively related to the difference between osmolarity in water and serum osmolarity. The urea nitrogen were elevated significantly with the rising 19.05,30.20,47.86,75.86mmol/L-ATPase in branchial epithelium wereserum osmolarity and alkalinity, significantly by salinity, alkalinity and interaction, the influence degree of the three effects the salinity was the greatest, followed by alkalinity, interaction. The gill Na+/K+-ATPase activity increased in the beginning and decreased subsequently, the highest value of ATPase was in orthogonal group of salinity 10g/L and alkalinity 30.20mmol/L. We can draw a conclusion that can survive in single salinity below 12g/L and two factor of salinity 10g/L and alkalinity 30.20mmol/L.}