We examined food habits of Tylonycteris pachypus and T. robustula by fecal analysis in 2 counties of Guangxi, South China. The diet of T. robustula included 7 orders of insects: Hymenoptera (62.3% by volume), Diptera (29.6%), Coleoptera (6.0%), Hemiptera (1.5%), and traces of Orthoptera, Trichoptera, and Ephemeroptera. The diet of T. pachypus included all the main orders consumed by T. robustula (53.4%, 29.0%, 13.4%, 2.1%, respectively) and 3 other orders: Homoptera, Blattodea, and Embioptera. No differences were found in diets of males and females of either species. The diet of T. pachypus showed clear seasonal variation from spring to autumn and differences in diet between the different geographical areas studied. There were no differences in the 4 dominant insect orders consumed by both species in Longzhou County, but insects consumed by T. pachypus were characteristically smaller than those eaten by T. robustula, and food-niche breadth (based on prey size) also was smaller than that of T. robustula.