A bilirubin oxidase (EC 1.3.3.5) producing strain, Mv 2.1089, was isolated from several strains of Myrothecium verrucaria by dilution method. The optimum conditions of enzyme production were investigated and the results were as follows: the suitable medium was cultured at 25℃ on a rotatiag shaker glucose and peptone, at pH 6.0. The strain was cvltured at 25℃ on a rotating shaker (150 r/min) for 96 h. Bilirubin oxidase with 0.5—1.5 u/ml was obtained in the culture medium.