Abstract:[Objective] To obtain a fungus capable of reducing N, N-dimethyl-3-keto-3- (2-thienyl)-1-propanamine (DKTP) to (S)-DHTP, a key precursor to synthesize Duloxetine. [Methods] Routine and an improved biotransformation method were used to screen fungus from soil, and the type of the fungus was identified by analysis of morphological characters and DNA sequence of 26S rDNA. [Results] A fungus was obtained which was capable of asymmetrically reduce DKTP to (S)-DHTP with high yield (more than 90%) and high enanti-ometric excess (more than 99%), and the improved method was more convenient and efficient. The identification showed that the fungus belong to the Genus of Rhodotorula Harrison, and was named as Rhodotorula sp. 507. [Conclusion] The screened fungus could efficiently and asymmetrically reduce DKTP to (S)-DHTP, which makes it possible to get enough precursor for the synthesis of Duloxetine easily and economically.