Diet composition and foraging ecology of Asian elephant were studied in its natural habitat in Shangyong National Natural Reserve, Xishuangbanna, China, through field observation and dung analysis, from 1998 to 2000. A total of 106 species were recorded as being eaten by Asian elephants, among them 83 species were identified in elephant’s dung. Plant families that contributed a major proportion of elephant’s diet in the study area were: Gramineae (8 spp., 10.0%), Moraceae (7 spp., 9.9%), Papilionaceae (4 spp., 8.4%), Araliaceae (3 spp., 6.6%), Vitaceae (3 spp., 5.7%), Apocynaceae (3 spp., 4.6%), Musaceae (1 spp., 4.2%), Zingiberaceae (3 spp., 3.7%), Myrsinaceae (3 spp., 3.6%), Rosaceae (3 spp., 3.6%), Euphorbiaceae (5 spp., 3.3%), Ulmaceae (2 spp., 3.0%) and Mimosaceae (4 spp., 2.9%). The most important plants in elephants’ diet are Ficus spp. (Moraceae, 9.0%), Dendrocalamus spp. (Gramineae, 4.5%), Musa acuminata (Musaceae, 4.2%), Microstegium ciliatum (Gramineae, 3.5%) and Amalocalyx yunnanensis (Apocynaceae, 3.1%). Asian elephants consumed a variety of plants in terms of life form, including tree, vine, shrub and herb. Early successional species comprise a higher proportion of diet than late successional plants (42 spp. taking 59% vs. 32 spp. taking 37%). Browse species contributed a larger proportion of diet compared to grazing species (77 spp. taking 91% vs. 6 spp. taking 9%). The number of plant taxa (species, genus, family) in elephant’s diet each month is negatively correlated with monthly rainfall and mean temperature. The study may help to develop proper strategies for wildlife management especially referring to the human-elephant conflict, which is now a serious issue in the conservation of Asian elephants in this area.