MDRTB has been made by treatment failure and has also spread by its contagiousness. I tried to explain how to make MDRTB clinically, and also tried to propose how to prevent it from spreading in a hospital. At first, a principle of modem chemotherapy against tuberculosis was elucidated, i.e. "bi-phase method of treatment." Danger of mono-therapy, particularly functional one, was warned through a case report. Thus acquired drug-resistance was made, single at first, multi-drug thereafter. According to the increase of patients of acquired MDRTB, primary MDRTB patient has emerged through the direct contagion. We reported nosocomial outbreak cases of MDRTB, including re-infection to patients with pan-sensitive tuberculosis. Therefore, strict isolation of MDRTB with smear-positive sputum must be instituted in a tuberculosis ward. All smear-positive tuberculosis patients should be isolated in a room against air-borne infection just in case of MDRTB. There are, however, not enough isolation rooms in tuberculosis ward in Japan. Rapid detection of rifampicin-resistance through the gene analysis must be done in this situation.