14 spp. are recorded, of which Orthetrum t. triangulate (Sel.) is new for Hongkong. Idionyx victor sp. n. (holotype <5: Hongkong, New Territories, Chuk Yueng, 24-VI-1988) is described and compared with I. yolanda Sei., I. thailandica Hämäläinen and I. philippa Ris.