Abstract: We compared the effects of different carbon sources, nitrogen sources and inorganic salts on fermentation yield of oceanic red yeast (Rhodotorula sp.)RH1. By 4 factors and 3 levels orthogonal test, the optimum fermentation conditions for RH1 were determined: peptone 10 g · L^-1, yeast extract 15 g · L^-1, glucose 20 g · L^-1, MgSO₄ 0.25 g · L^-1, KH₂PO₄ 0.25 g · L^-1, NaCl 10 g · L^-1, inoculation amount 10%, initial pH 5.0, temperature 28 ℃, 80 mL medium in 500 mL triangle bottle, and fermentation time 48 h. Under above conditions, the cell biomass of RH1 can reach 10.46×10⁸ cfu · mL^-1, which increases by 23.9% as compared with the fermentation before optimization. An experiment of expanded culture is also conducted in a 25 L fermentation tank. The cell biomass of RH1 increased to 33.6×10⁸ cfu · mL^-1 in 28 h under the conditions of inoculation amount 8%, initial pH 5.0, revolution speed 350~400 r · min^-1, air ventilation volume 9 L · min^-1 and temperature 28 ℃. It is expected to further increase the biomass of strain RH1 by continuous filling of the materials.