Abstract: Understory birds were sampled by mist nets in monsoon evergreen broadleaved forest of Mengyang, Xishuangbanna, Yunnan from October 2008 to March 2009. A total of 1423 individuals of 90 species representing 28 families and 7 orders were captured. The dominant birds were Sliver-breasted Broadbill (Serilophus lunatus), Brown-cheeked Fulvatta (Alcippe poioicephala), White-throated Bulbul (Alophoixus pallidus), Golden-spectacled Warbler (Seicercus burkii), White-tailed Robin (Cinclidium leucurum), Black-breasted Thrush (Turdus dissimilis), Streak-Breasted Jungle Babbler (Pellorneum ruficeps), and Buff-breasted Jungle Babbler (Trichastoma tickelli). Resident birds, the major species of the understory, accounted for 89.3 percent of total captures. The mean capture rate was 9.0 individuals/(100 net-hours). The capture rate differed significantly between months, highest in December 2008 (12.5±1.3）individuals/(100 net·hours), lowest in February 2009 (5.2±0.6 )individuals/(100 net·hours). One important characteristic is more species richness and lower density of birds in Xishuangbanna compared to understory bird composition of South China. Another characteristic is lower babblers' abundance. Sliver-breasted Broadbill, National Key Protection Bird, is one of dominant birds. Thus its habitate conservation needs further concern in Xishuangbanna.