A　tuberculosis　model　with　incomplete　treatment　is　investigated.　It　is　assumed　that　the　treated　individuals　may　enter　the　susceptible　compartment　due　to　complete　treatment,　or　enter　the　latent　compartment　due　to　the　existence　of　tubercle　bacillus　for　incomplete　treatment,　even　enter　the　infectious　compartment　due　to　the　failure　of　treatment.　The　basic　reproduction　number　is　obtained,　and　it　has　been　shown　that　the　dynamics　of　the　model　is　determined　by　its　basic　reproduction　number.　If　the　basic　reproduction　number　is　less　than　or　equal　to　one,　there　exists　only　the　disease-free　equilibrium　which　is　globally　asymptotically　stable,　and　the　disease　dies　cut　eventually.　If　the　basic　reproduction　number　is　greater　than　one,　besides　the　unstable　disease-free　equilibrium,　there　exists　a　unique　endemic　equilibrium,　and　the　disease　is　uniformly　persistent.