Abstract: Effects of extracted liquid of \%Laminaria japonica\%,KNO\-3,CuSO\-4 and ZnSO\-4 on fatty acid content of marine yeast were studied by means of orthogonal test. Results showed that fatty acid compositions and levels of the marine yeast varied among the treatments. KNO\-3 was the first limiting factor for n-3 series polyunsaturated fatty acids (PUFA) content and total lipid level of the yeast and ZnSO\-4, and extracted liquid of \%Laminaria japonica\% were the second limiting factor affecting yield and net n-3 series PUFA content in the yeast. There was no significant influence on n-3 series PUFA compositions among the treatment. The synthesis path of n-3 series PUFA and factors influencing lipid metabolism and production of n-3 series PUFA in the yeast were discussed.