Abstract: Objective To observe the effect of reducing incidence of TB by prophylactic chemotherapy in cases with coal-pneumoconiasis.Methods 269 cases with stage Ⅰ,Ⅱ of coal-pneumoconiasis were devided to 3 groups and to take INH,RFP and placebo respectively for 3～6 months.Results Through after 5 years observation showed the incidence of TB was reduced signifficanly in the group A and group B (take INH or RFP) than The control group(P<0.01).Conclusion The prophylactic chemotherapy(INH,RFP) will reducing the incidence of TB in patients with coal-pneumoconiasis effectively.

Key words: Tuberculosis,pulmonary, Coal-pneumoconiasis, Prophylactic chemotherapy