Contrary to other infectius diseases, the antibody production in vivo is very low in candidiasis. Healthy individuals harbor Candida albicans saprophytically, and therefore has serologically less specificity.As an immune reaction for Candida, agglutination test has generally been used. However, it tends to give a spontaneous agglutination. It is slso known that a cross agglutination would occur between Candida and bacteria strains or among Candida strains themselves. Akiba and Ata reported that a cross reaction was observed between Candida albicans and Mycobacterium tuberculosis. A series of experiments was therefore carried out to study a common antigen for tubercle bacillus and Candida albicans.