Abstract: Haematococcus pluvialis is an excellent algae species for production natural astaxanthin. Optimizing the nutrients composition of the culture medium is important to improve the density of algal cells and astaxanthin content. A single-factor test was conducted to screen the optimal concentration range of NaNO₃, MgSO₄·7H₂O, K₂HPO₄·3H₂O and Na₂CO₃, and the medium was optimized using the response surface methodology and validation tests. The results showed as the followings:（1）The mass concentration of NaNO₃, MgSO₄ ·7H₂O, K₂HPO₄ ·3H₂O and Na₂CO₃, were in the ranges of 1 500-2 000, 80-640, 20-60 and 20-80 mg·L^-1, respectively. The most promoting effects on algal cell density were in the order of NaNO₃, Na₂CO₃, K₂HPO₄ ·3H₂O, MgSO₄ ·7H₂O.（2） The optimal nutrient concentrations respectively were 1 556.42, 51.43, 42.18, and 358.59 mg·L^-1. The interaction between K₂HPO₄·3H₂O and MgSO₄ ·7H₂O was significant（P＜0.05）.（3） Cultured H. pluvialis for 8 days in the optimized medium, the Fv/Fm of PS Ⅱ and Chl-a content of the algae cells were 0.69 and 7 268.97 μg·L^-1,respectively, which were both highly significant higher than that in the control group（P＜0.01）, and the cell density was 3.53×10~5m L^-1, which was significantly higher than the control by 20.48%（P＜0.05）.