Abstract: This study was performed to evaluate the relationship between the infection of tubercle bacillus（TB）and Behcet’s disease.Serum anti-purified protein derivative antibody（A-PPD）was determined in 44 cases with BD,30 cases with Connective Tissue Disease（CTD）（including systemic lupus erytematosus,rheumatoid arthritis,ankylosing spondylitis,adult onset still’S disease）and 60 healthy controls（HC）by EI,ISA,The results showed a higher positive rate of A-PPD in BD group（41%）than those of the CTD group（6.66%）and HC group（0%）（P＜0.01）,We also found the strong positive results of tuberculin skin tests appeared in 20（45%）cases with BD.Among them,16（36%）cases presented clinical active tuberculo-sis or had history of tuberculosis.The good efficacy of anti-tuberculosis drugs were observed in 22（50%）cases with BD.We conclude that infection of TB rnay be one of the etiological factors of BD.