In the present nine species of marine green algae from the Xisha Islands are reported. A new species Boodleopsis aggregata is deseribed and six species, namely,Bryopsis harveyana J. Ag, Codium arabicum Kuetz.,C.repens (Crouan)Vickers, C.geppei O. C. Schmidt, C. taitense Setchell and Caulerpa nummularia (Harv. )Rke.,are new records for the Xisha flora, the latter two species being reported for the first time for the Chinese flora.