With the detecting of ethanol by ethanol sensor, the effects of ethanol on cell growth andastaxanthin production by Phaffia rhodozyma JMU-MVP14 were investigatedin shake flask. The results indicatedthat 1~2 g/L ethanol was conducive to astaxanthin accumulation in 10 g/L or 20 g/L glucose initial medium, while high concentration of alcohol inhibitedthe cell growth and astaxanthin production of Phaffia rhodozyma. When ethanol concentration was maintained at 2 g/L by ethanol sensor in 10 g/L glucose initial medium, astaxanthin production was 50.1 mg/L, which increased by 20.3% compared with the control group.The yield of astaxanthin in a cell was 13.1 mg / g and the utilization rate of glucose was over 77.2%.This demonstrated that the constant ethanol control strategy was conductive to astaxanthin accumulation in yeast cells. The maximum yield of astaxanthin was 55.3 mg/L under the optimized condition of 10 g/L initial glucose concentration, 2 g/L constant ethanol concentration and 5 g/L glucose supplemented per 24 h during the fermentation.And the yield of astaxanthin in a cell was 19.7 mg / g, which increased by 39.7% compared with the control group (14.1 mg/g).