PURPOSE: To provide a strain of Phaffia rhodozyma capable of producing astaxanthin at a high level and provide a new method for growing the Phaffia rhodozyma and a new method for producing astaxanthin included in Phaffia rhodozyma and suitable for the use for supplying a food color.

CONSTITUTION: A mutant capable of producing astaxanthin at a high level is developed by culturing an astaxanthin-producing strain of Phaffia rhodozyma in a medium added with nitrosoguanidine (NTG) or ethyl methanesulfonate(EMS). Astaxanthin in Phaffia rhodozyma can be completely utilized by using an enzyme newly found in Trichoderma harzianium and capable of effectively digesting the cell membrane of Phaffia rhodozyma.