Abstract: Data on the diet were collected from one group of Francois' langurs(Trachypithecus francoisi)between October 2005 and July 2006at Nonggang Nature Resereve,Guangxi province,using instantaneous scan sampling.To explore the influence of water content in food on langur's food choice,watercontents of the food species were measured,and the relationship between water contents of the food species and their consumption were analyzed.The results indicated that there was significant variation in the water contents of different plant parts eaten by langurs.Immature leaves had the largest value of water content,which accounted for 71.52%,followed by mature leaves for 66.25%,and fruits had the lowest value 63.42%.The monthly mean water content in plant food showed significant variation,ranging from 61.59% to 72.59%.However,there was no significant difference in the mean water content in plant food according to season.The relationships between the monthly feeding time for leaves of different plant species andtheir corresponding water content were tested,and significant correlations in November and December were found.This indicated that water content of the food maybe one of the factors influencing the food choice of the Francois' langur in Karst habitat,especially in the dry season.

Key words: Francois' langur, water content in food, food choice, karst habitat