To produce ergosterol Saccharomyces sake KBA No. 6 was used and various factors related to ergosterol accumulation were investigated. The most effective inorganic nitrogen source was ammonium chloride and 3.50 % of ergosterol was accumulated in the cell when the C/N ratio was 200/1. When Tween 80 and potassium nitrite were used simultaneously, ergosterol content and total amount of ergosterol were increased by 56 % and 45 %, respectively, compared to their control in which 0.2 % of Tween 80 and 0.1 % of potassium nitrite were used. Under the optimum conditions, ergosterol content increased from 1.73 % to 5.3 % and the total amount of ergosterol was increased from 65.2 ㎎/1 to 135.15 ㎎/1.