Abstract: Based on the peripheral blood leukocyte cDNA library constructed by suppression subtractive hybridization (SSH) in our lab, bovine βdefensin 5 gene (BNBD5) was chosed as one of the candidate genes. The aim of the current research was to look for molecular events and establish fundamental materials and techniques for further study. Finally, the coding sequence (CDS) of BNBD5 gene was successfully amplified. The Pichia pastoris expression vector was constructed and the BNBD5 protein was expressed. This research lays the foundation for preparation of antibodies of BNBD5.