Gastrochilus balangshanensis, a new orchid species from the Balang Mountain, Sichuan Province, Southwest China, is described and illustrated. It morphologically resembles G. affinis, but differs in having shorter stems, a reniform epichile and a sub-hemispherical hypochile (spur), obtuse-rounded at the apex. The results of molecular phylogenetic analyses based on nuclear ribosome internal transcribed spacer (nrITS) and four chloroplast DNA markers (matK, psbA-trnH, psbM-trnD and trn L-F) from 50 Gastrochilus species indicate that G. balangshanensis is closely related to G. heminii and G. bernhardtianus, also endemic to the Hengduan Mountains. The novelty is a branch and trunk epiphyte in mixed coniferous forest.