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Haematococcus pluvialis is a freshwater species of Chlorophyta and is currently investigated with respect to its ability to accumulate the strong antioxidant astaxanthin under stressful conditions. The study of its lipid content has not been addressed by the scientific community, however, H. pluvialis has some advantages that would help in achieving lipid biomass, for example, is tolerant at pH>9, its cells diameter can reach approximately 70 µm which facilitate filtration and the natural flocculation. Therefore, the goals in this study were to assess the physiological performance of H. pluvialis aiming to obtain the period of highest biomass accumulation lipid. The strain used was Haematococcus pluvialis UTEX-2505 and the factors evaluated were: temperature controlled in a growth chamber at 28°C and constant stirring (60 rev min-1), intensity of radiation (photoperiod of 12h), nitrogen e sodium acetate under three levels added to liquid Bold’s Basal Medium (BBM). The initial concentration of inoculums was adjusted to 103 cell mL-1. Samples were collected daily to assess the optical density until it was observed a decrease in cell concentration. About 48 h after inoculations, medium with addition of sodium acetate had an increase in the pH from 7.0 to 9.0, which increased the turbidity of culture medium. Treatments with N in the medium maintained the pH ranged from 7.5 to 8.0. It was found that with the increase in pH value cells still growing and did not produce cysts. The rate of cells growth was in average of 1.5 d-1 and the total lipid content in the microalgae biomass, detected by fluorescence emission spectroscopy using Nile Red, was higher in the exponential phase of growth.ഀ Suported by “Energy Company of Parana (COPEL) – Brazil; Foundation for Research Support and Development of Brazilian Agribusiness (FAPEAGRO) – Brazil and Brazilian National Higher Education Coordinating Council (CAPES) – Brazil”.ഀ