Abstract: 16 α-Methyl-3 β,17 α-dihydroxy-5 α-pregnane-20-one-3 β-acetate (Ⅰ) was prepared from tigogenin and then incubated with a mixture of Mycobacterium smegmatis (MS₁) and Arthrobacter simplez (A₁) to give 16 α-methyl-17 α-hydroxy-△^{1, 4}-pregnadiene-3,20-dione (Ⅱ) with about 63% yield.Compound (Ⅱ) when incubated with Absidia glauca (AG₁) gave about 55% yield of 16 α-methyl-11 α, 17 α-dihydroxy-pregna-1,4-diene-3,20-dione (Ⅳ).