To explore the influence of habitat fragmentation on the ecology of the François's langur ( Trachypithecus francoisi
), data on habitat use were collected from a group of François's langurs living in an isolated hill in the Fusui Rare Animal Nature Reserve, Guangxi Province, from March to December 2001. To identify the effect of human activities on vegetation, 10 vegetation quadrats were sampled in the habitat, including 5 on the slopes with more human disturbance, and 5 on the hill-tops with less human disturbance. Because of human destruction, not only the number of plant species, diversity and density, but also the densities of preferred foods for François's langurs were less on the slope than those on the hill-top. Analyses of habitat use indicated that the langurs showed preference for the hill-top with abundant food resources and less human disturbance, and avoided to use the slope with more human disturbance. In the rainy seasons, langurs spent significantly more time on the hill-top rather than on the cliff. Therefore, habitat selection and use of the species may be resulted from the balance of feeding benefit and human disturbance. François's langurs used the platforms and caves on the cliffs as sleeping sites. They reused some sleeping sites, and tend to use the same caves on consecutive nights.