Abstract: Dunaliella salina a β-carotene accumulating halotolerant algae has been analyzed for the effect of various growth conditions on its antioxidant vitamin contents β-carotene, tocopherol and ascorbic acid. Vitamin contents of Dunaliella salina grown in culture contained sufficient nitrogen (70 ppm N ) and NaCl ( 10 %) under optimum light intensity 200 W were 1.78, 0.7 and 0.25 %, respectively. Increasing salt concentration (NaCl ) to 30 % and high light intensity (400 W ) increased vitamins content to 6.43, 0.45 and 0.95 %, respectively. The maximam accumulation of antioxidant vitamins occurred in Dunaliella salina was observed when the cells grown under combined stress conditions high NaCl concentration, high light intensity with nitrogen deficiency (5 ppm ). β - carotene, vitamin E and vitamin C percentages were 13.14, 1.23 and 2.5 %, respectively. These values represented 738,1751 and 1000 %, respectively when compared with values of Dunaliella salina grown under optimum conditions (70 ppm N, 10 % NaCl and light intensity 200 W). The results showed that Dunaliella salina could be a potential for mass production of antioxidant vitamins.