Xanthomonas campestris belong to Gram-negative bacteria,which mainly damage cruciferous vegetables and economic forests including walnuts and mangosteens,causing great economic losses to agricultural and forestry crops and seriously harming the healthy development of the agricultural and forestry industry. Secreted proteins play an important role in the pathogenic process of plant pathogenic fungi,bacteria,and oomycetes. There is no reports on the physicochemical properties and characteristics of secretary proteins of Xanthomonas. This study uses the secretary protein sequences of X. campestris B100, X. campestris pv. campestris str.8004,and X. campestris CN14 from the published genome-wide sequence as the basic data,and uses Protscale,SMART,TargetP 2.0 Server,and other bioinformatics software to analyze the physicochemical properties,conserved domains,and transit peptides of the secretary proteins above-mentioned. The results showed that there was no obvious rule between the theoretical isoelectric point of secretary proteins and the length of amino acids in X. campestris. An average 44.73% of the protein is unstable protein. An average of 83.21% of the protein has a total average hydrophilicity of less than 0,which is a hydrophilic protein. The number of proteins with obvious conserved domains in each secretary protein of Xanthomonas is 12 on average. All secretary proteins have signal peptides. The distribution of transit peptide prediction possibilities is relatively even.