Induction of mutations is an alternative for genetic improvement of sugarcane (Saccharum spp. hybrid). It has been used to obtain mutants with resistance to rust (Puccinia melanocephala). Characteristics of pathogen infection process were identified through histopathological studies in a mutant (IBP 8518) of the B4362 variety, with resistance to this disease. Fragments of leaves were inoculated with P. melanocephala . Then, these were stained with lactophenol tripan blue to observe, in the optical microscope, the autofluorescence of the dead cell as hypersensitive response. The essay demonstrated fist that resistance of mutant involves a hypersensitive response at the place of interaction with the fungus. The it does not depend on possible structural changes of the leaf surface. Histological characterization of this incompatible interaction could contribute to the study of molecular processes of resistance to P. melanocephala in sugarcane. Keywords: histology, hypersensitive response, mutant