Lutein pigment is one of the valuable carotenoids found in many algae and plants, known for its antioxidant properties and its therapeutic role, especially in eye health and its use as a natural colorant in food and in many pharmaceutical uses. The current study aimed to determine the effect of nitrate and phosphate on the amount of lutein produced by algae to evaluate the effectiveness of the resulting lutein as an antioxidant to protect cells from free radicals. The results of the present study indicated that the highest value of lutein in Coelastrella saipanensis was 0.562μg/ mg at 0.01 and 0.02g/ L concentration of nitrate and phosphate, respectively, while the lowest value of lutein was 0.1303 and 0.13μg/ mg without adding nitrate and phosphate to the medium (0g/ L). The results of statistical analyses were supported at P<0.05, indicating differences in lutein production. The antioxidant activity results using the DPPH assay indicated that lutein had high antioxidant activity, with the lowest antioxidant activity of 18% recorded at lutein concentration of 10μg/ mL, while the highest antioxidant activity was recorded at lutein concentration of 35μg/ mL, reaching 48%. The results showed the importance of controlling nutrients, especially nitrate and phosphate, and providing appropriate growth conditions and concentrations in the growth medium to increase the production of lutein and also indicated the properties of this pigment as an antioxidant against free radicals and thus its potential use in many natural pharmaceutical formulations.