Abstract: Structure and function of Mmc-3740 encoded protein of Mycoplasma mycoides subsp. capri were studied based on the bioinformatics of the secondary structure, transmembrane region and signal peptide of the gene. The results showed that the protein was an alpha helix with extended random coil, and that the signal peptide located either extracellular or in cytoplasmic with high antigen index and immunogenicity.The area that showed high antigen index and immunogenicity concentrated in the regions of 28-51, 60-67 and 80-130 amino acid sequences.The molecular formula of the protein was C₆₀₇H₁₀₀₀N₁₈₄O₂₆₁S₅ with a molecular weight of 15.21 kD and an isoelectric point of 4.42.The half-life of Mmc-3740 in microorganisms appeared to be short and unstable.