Abstract: The chromosome number and karyotype of 14 species in 11 genera of the Orchidaceae was studied . The results showed that Acampe papillosa is 2 n = 2 x = 36m + 2sm; A. rigida 2 n = 2 x = 32m + 6sm; Arachnis labrosa 2 n = 2 x =34m+ 4sm; Cleisostoma simondii var. guangdongense 2 n = 2 x = 32m + 6sm; Doritis pulcherima 2 n = 2 x = 30m + 8sm; Gastrochilus acinacifolius 2 n = 2 x = 38m; G. calceolaris 2 n = 2 x = 38m; G. obliquus 2 n = 2 x = 38m; Holcoglossum subulifolium 2 n = 2 x = 38m; Kingidium deliciosum 2 n = 2 x = 30m + 8sm; Luisia morsei 2 n = 2 x = 24m + 12sm + 2st; Pomatocalpa spicatum 2 n = 2 x = 36m+ 2sm; Rhynchostylis gigantean 2 n = 2 x = 36m + 2sm; and Robiquetia spathulata 2n = 2x = 36m + 2sm. The system and evolution in the Orchidaceae was briefly discussed based on our results .

Key words: Orchidaceae