Abstract:  The elementary fermentation conditions was obtained through a series of single factor tests. Based on the analysis of these results, the optimal culture conditions were confirmed by orthogonal test. The results showed that the optimum conditions are culture temperature 28 ℃, original pH 7.0, the ratio of strain(+) to strain (-)1:1, inoculum size 6%, and culture time 156 ～162 h. On the optimum conditions, the yield of β-carotene increased by 117.3% compared with the original fermentation conditions, up to 772.47 mg/L, which pave the groundwork for future industrialization.

Key words: Blakeslea trispora； &beta, -carotene； biosynthesis； orthogonal design ..；