Four NaHCO₃ alkalinity gradients which were 3.20 mmol/L (control group), 7.73 mmol/L, 12.60 mmol/L and 16.67 mmol/L were set for breeding of 3-month-old hybrid sturgeons(Huso dauricus♀×Acipenser schrenckii♂) for 60 days to compare the effects of alkalinity on survival rate(SR), growth and serum biochemical indices of juvenile hybrid sturgeons. The results are shown as follows: that the time of first dead individual in each group was negatively correlated with alkalinity; the average survival rate of each group was 70.14%, 64.1%, 28.21% and 51.52%, respectively, the mortality of 12.60 mmol/L and 16.67 mmol/L experimental groups was higher than that of the control, with extremely significant difference; the body weight gain, body length gain ratio and feed conversion ratio of each group were extremely significantly lower than those of the control with extremely significant difference; the serum biochemical indices of 7.73 mmol/L, 12.60 mmol/L and 16.67 mmol/L groups were significantly lower than those of the control,the levels of serum total protein (TP), high density lipoprotein cholesterol (HDL) and triglyceride (TG) of 12.60 mmol/L and 16.67 mmol/L groups were significantly lower than those of 7.73 mmol/L and the control,the total cholesterol (TCHO), serum hydrogen phosphate (HCO^-₃) and serum calcium (CA) of the experimental group were significantly lower than those of the control, while the serum creatine kinase (CK) and creatinine (CREA) of the experimental group were significantly higher than those of the control with significant difference. In conclusion, high alkalinity may affect the synthesis and metabolism of protein and lipid in hybrid sturgeon, cause slow impairments to cardiac,hepar and kidney tissues, inhibit its growth and even cause individual death. It is concluded that juvenile hybrid sturgeon can be safely cultured in water with alkalinity of 7.73 mmol/L and below, and the suitable alkalinity range can be increased through domestication and adjustment of seedling specifications.