The present invention is a novel non saline medium for the production of Betacarotene and other carotenoids from cultivating Dunaliella salina. The novel medium developed using only Magnesium sulphate 3-10m preferably 8m with other ingredicnts ca²+ preferably 0.02mM, phosphate preferably 2uM, NO3- preferably O.O8mM, phosphate preferably O.4mM and carbonates as HCO3" preferably O.OO6M for the cultivation of Dunaliella salina and cultivating alga Dunaliella salina in the said medium in open ponds exposed to sunlight at pH between 7.5-8.5 and tomperature. about 32-45ºC. The cultivation of alga Dunaliella salina in the said medium produces about 6% dry weight basis of carotene. The extracted protein has higher protein content, use as feed supplement for animal feed.