Donalilla algae, especially Donalila salina, is one of the most studied algae cultivars for mass cultivation of Donalila as a food source. Methods: Culture medium conditions with salinity (1, 3 and 5 M), light intensity (35, 127.5 and 220 μmol) and nitrogen source (200, 500 and 800 mmol / l) on the level of antioxidant activity (DPPH) Donalilla salina was optimized. Therefore, 15 treatments were designed according to the Bonken box response level method in 16 minitabs. Results: The results showed that different culture conditions (salinity, light intensity and nitrogen content) had a significant effect on the amount of antioxidants in Donalilla salina so that the amount of antioxidants decreased significantly with increasing nitrogen in algae culture medium. And increased significantly with increasing salinity and light and varied in the range of DPPH 18.02 to DPPH 20.95. Conclusion: The highest level of antioxidants (20.79% of DPPH) can be achieved by creating optimal conditions of light irradiation of 165 micromol photons, salinity of 3.34 M and nitrate concentration of 375.75 macromol per liter.