Abstract: The present paper reports the chromosome numbers of 12 species in Orchidaceae from China. The results are as follows: Bletilla striata (Thunb.) Rchb. f. 2n= 32, Calanthe discolor Lindl. 2n=40, Calanthe hamata Hand. -Mazz. 2n=40, Cephalanthera erecta (Thunb.) Bl. 2n=34, Cephalanthera falcata (Thunb.) B1. 2n=34, Changnienia amoena Chien 2n=46, Cremastra appendiculata (D. Don) Makino 2n = 42, Dendrobium moniliforme (L.) Sw. 2n=38, Gastrodia elata Bl. n=15, 18, Liparis dunnii Rolfe 2n= 20, Platanthera minor (Miq.) Rchb. f. 2n=42, Pleione bulbocoidioides (Franch.) Rolfe 2n=40.

Key words: Orchidaceae, Chromosome number