This attempt was made to examine the anti-lung antidody production in the experimental tuberuculosis of the lung in rabbits. The results summarized as follows; 1. Anti-lung-antidobodies were increased in titer in parallel with the development of the experimental lung tuberuculosis lesions. 2. In the experimental lung cavity formations rabbits were inoclated intracutaneously with human type killed tuberuculous bacillus (H37RV), ovalbumin and homologous lung emulsion and 1 week after inoculations with above described antigens, the injection was made aseptically into the lung of sensitized rabbits with the emulsion of 4 mg human type killed tuberuculous bacillus suspended 1.0 ml incomplete djuvant. There were no significant differences in histological findings of the lung lesions among these experimentalanimals. 3. The close relationship between anti-lung-antibody and complete tuberuculin antibody was seen, and was similar to that ofhuman lung tuberuculosis patients.