Abstract: Objective To understand the prevalence of drug resistant tuberculosis (TB) and related rosk factors in Haimen, Jiangsu province, and provide evidence for the prevention and treatment of drug resistant TB. Methods Sputum culture was conducted for all the 336 smear positive TB patients seeking medical care in Haimen TB prevention and treatment institution from October 2009 to September 2013. Pathogen identification was conducted, and drug susceptibilities of Mycobacterium tuberculosis to 4 first line anti TB drugs isoniazid, rifampicin, ethambutal and streptomycin were tested. Results A total of 310 M. tuberculosis strains were cultured during this period. The overall drug resistant rate was 24.5% among the isolated M. tuberculosis strains (76/310). The single drug resistant rate was 9.7% (30/310). The multi drug resistant rate was 2.9% (9/310), the extensive drug resistant rate was 11.9% (37/310). The overall drug resistant rate in re-treated smear positive patients was higher than that in initial treated smear positive patients (2=55.294,P0.005, 2=71.471,P0.005). Among the strains from smear positive patients, the resistant rates to isoniazid and streptomycin were high (46.7% and 36.7%), the resistant rate to isoniazid+ streptomycin was 88.9% and the resistant rates to isoniazid + rifampicin and isoniazid + rifampicin + streptomycin were high 46.0% and 29.7%, respectively. Conclusion The prevalence of extensive drug resistant TB is high in Haimen, it is necessary to strengthen the case finding and treatment of extensive drug resistant TB. Re-treated TB patients are at higher risk to develop drug resistance, it is important to conduct standard treatment.