The total RNA was extracted from the venom gland of snake, Gloydius shedaoensis. The defibrase cDNA was amplified by RT-PCR. Assaying the nucleotide sequence of the cDNA allowed the complete amino acid sequence for defibrase of Gloydius shedaoensis to be determined. The defibrase cDNA was inserted into the vector, pPIC 9K, and expressed in Pichia pastoris which then produced 10 mg target protein l(-1).