Abstract: [Objective] To isolate and identify Xinjiang Brucella melitensis,this project focuses on prokaryotic expression of the L7/L12 protein of the bacteria,detection of its reactionogenicity and and partial biological analysis.[Method]Isolation and identification of Brucella melitensis by using bacterial streak culture,morphological observation,biochemical test and PCR detection.Using conventional and molecular biological methods to express and purify the L7/L12 protein of this Brucella melitensis.Expression and purification isolate strain L7/L12 protein by using the conventional molecular biological methods,and analysis of the fusion protein reactionogenicity by Western Blot.Using bioinformatics software to analyze some functions of this protein.[Result]After identification,the strain was identified as Brucella melitensis.After enzyme digestion and sequencing,the expression vector pET-28a-L7/L12 was correctly constructed.SDS-PAGE tests showed that the purified L7/L12 protein was a single band.The fusion protein had good reactionogenicity by Western Blot detection.Bioinformatics analysis showed the protein had no trans-membrane domain and no signal peptide.Its secondary structure was mainlyα-helix.And the three-dimensional structure of the protein was constructed by Phyre2 Server.[Conclusion]The isolated strain was identified successfully and L7/L12 fusion protein of this isolate strain was expressed and purified.Blot Western test proved that the protein had a good reactionogenicity,which laid the foundation for the protein follow-up research of the subunit vaccine.