Liparis tianchiensis (Orchidaceae, Epidendroideae), a new species from Wenxian County, Gansu Province, China, is described and illustrated, based on morphological characters. Liparis tianchiensis is morphologically similar to L. damingshanensis, L. pauliana and L. mengziensis with erect, lax flowered-inflorescences, small persistent floral bracts, small greenish-purple flowers, spreading sepals, free reflexed and linear petals, a lip with 2 calli near the base and an arcuate column. Liparis tianchiensis differs from L. pauliana by the single and much smaller leaf, shorter sepals and petals, smaller and reflexed oblong lip. It differs from L. mengziensis by having fewer and larger flowers and not connate lip apex. The novelty mostly resembles L. damingshanensis, but can be readily identified by having longer sepals and a reflexed oblong lip. Liparis tianchiensis only occurs in evergreen broad-leaved forest around a mountain lake in Wenxian County, Gansu Province, China.
