Abstract: ObjectiveTo investigae drug resistance of Mycobacterium tuberculosis among floating population in Ningbo.MethodsAll sputum culture positive patients among migrant population confirmed in district tuberculosis dispensaries in Ningbo from 2007 to 2009 were enrolled.The drug susecptibility tests of inoniazid,rifampicin,streptomycin,and ethambutol were performed with proportion method.ResultsAmong all patients enrolled,659 had positive bacterial culture and drug susceptibility results.Of the 659 strains,565 strains were Mycobacterium tuberculosis and 94 strains were Mycobacterium nontuberculosis.The total frequency of drug resistance was 33.5% (189/565);the total frequency of multi-drug resistance was 6.4% (36/565).The initial drug resistance rate was 29.5% (149/505)and the initial multi-drug resistance rate was 4.4% (22/505).The acquired drug resistance rate was 61.7% (37/60)and the acquired multi-drug resistance rate was 23.4% (14/60).ConclusionThe prevalence of drug-resistant tuberculosis among floating population was relatively high in Ningbo suggesting the necessity to strengthen the tuberculosis control program among migrant population.