Clinical observation was performed on 56 cases of active tuberculosis combined with D.M., from January, 1986 to December, 1989 at Inchon tuberculosis hospital. The following results were obtained. 1. The active tuberculosis combined with D.M. was 5.7% of the active tuberculosis. 2. The male-female sex ratio was 4.6:1 and peak incidence of age was 50~69 years 3. In chest P-A view, the far advanced tuberculosis was most common and the tuberculosis with cavity was 71.4%. 4. In patten of the infiltration on chest P-A view, patch or confluent pattern was most common. 5. In chest P-A view, the improved cases within 6 months regardless of D.M. control were 39(69.5%)cases and 18(69.2%)cases among well controlled state, 7(70%)cases among fairly good controlled state, 9(75%)cases among not controlled state, and 5(62.5%)cases among worse cases had improved. As a results, D.M control was not significant influence in the tuberculosis treatment. 6. The cases who were resistant to 2 or more drugs were aggravated in the 50% cases.