Abstract: Two different culture appliances, photobioreactor and raceway circulating bioreactor, were used for mass culture of desert alga and the effects of two mass culture systems on the biomass and exopolysaccharidses of desert alga were comparatively studied, and the roles of temperature, pH value, culture time and nitrogen, phosphorus contents in the growth and polysaccharides accumulation of desert alga were simultaneously discussed. The results indicated that in the two mass culture systems from photobioreactor and raceway circulating bioreactor, the growth of desert alga presented different variation trend, but the polysaccharide contents of desert alga had the same fluctuant variation trends. And there were not the synchronous response between the desert algae biomass and the polysaccharide exudation when they suffered the same culture condition in respective culture system. Moreover, it was found that the culture conditions such as temperature, pH, nutrition and growth cycle had an important effects on the growth and polysaccharide production of desert alga.