Abstract: Plague is an important zoonotic disease that poses a serious threat to human health.In this experiment,in order to predict the structure and function of the plasminogen activator （Pla） gene and the possibility of being a dominant antigen,the genomic DNA of Yersinia pestis was extracted for the purpose of gene amplification,and the pMD19T-Pla cloning vector was constructed.Using bioinformatics software for the physical and chemical properties of the gene,affinity/hydrophilicity,transmembrane region,signal peptide,phosphorylation site,glycosylation site,conserved domain,secondary structure,tertiary structure,and B/T cell epitopes are predicted and analyzed.The results show that the Pla gene has a complete ORF,encoding 312 amino acids,Pla protein has a theoretical isoelectric point of 5.88 and an atomic composition of C₁₅₃₈H₂₃₀₇N₄₁₅O₄₈₆S₇.It is a stable protein that does not contain a transmembrane region and has a signal peptide at the 1st to 23th amino acid positions.The hydrophilic protein contains a total of 48 phosphorylation sites,of which the serine phosphorylation site is the highest.The secondary structure is mainly composed of extended chains and random curls,accounting for 28.21%and 47.44%,respectively.Antigen epitope prediction shows that the protein contains more B-cell epitopes,which are located at 29～35,43～50,54～61,96～125,127～136,141～149,177～182,184～230,233～244,266～302 amino acids.Analysis shows that the Pla protein has good biological characteristics and antigenicity.This study has laid a solid foundation for the development of new Yersinia pestis vaccine and screening of candidate antigens.