A group of François' langurs (Trachypithecus francoisi) was studied in the Nonggang National Nature Reserve, southwest Guangxi, China, from September 2005 to August 2006. An instantaneous scan sampling method was used to collect data on patterns of habitat utilization. The aim of this study was to explore habitat selection by langurs living in a limestone forest. The results indicated that the langurs did not exploit their habitat uniformly and preferentially used particular microhabitats (χ²=43.063, df=4, P < 0.001). For example, the langurs were observed most frequently on cliffs (36.67% ±9.44% of the total record), followed by hill slopes (32.30% ±9.57%), hill bottoms (14.15% ±5.01%), flat zones (11.24% ±8.42%), and hill-tops (5.63% ±2.92%). We found no evidence of seasonal variation in patterns of habitat use (Hill-top:Z=-0.160, P=0.837; Cliff:Z=-0.320, P=0.749; Hill slope:Z=-0.480, P=0.631; Hill bottom:Z=-1.601, P=0.109; Flat zone:Z=0, P=1). However, individual microhabitats were used by the monkeys for different activities. The cliffs were frequently used as resting sites, and the hill slopes and the hill bottoms were used as both moving and feeding sites. Langur habitat use also was influenced by food availability, dietary composition, and climate. When the availability of flowers decreased, the langurs increased the time spent exploring the hill bottom. As flower consumption and mature leaf consumption increased, there was a correlated increase in the use of hilltops. In contrast, when exploiting fruits and seeds, langurs increased the time spent on hill bottoms and hill slopes. Similarly, the frequency of moving on cliffs increased in response to a decrease in the availability of young leaves. The frequency of feeding in the flat zone increased with the availability of fruits. In addition, there was a negative relationship between the average low temperature recorded during the day and the frequency that langurs fed in the flat zone. Our results indicate that the pattern of distribution and quantity of food resources acts as an important determinant of habitat use in François' langurs inhabiting limestone forests in southwest Guangxi. Patterns of habitat use in this primate species may reflect a trade-off between foraging benefits and predation risks.