Four species of crustose coralline algae from the Xisha Islands are described in the present paper. Among them, Fosliella farinose (Lamx.) Howe has been reported. from Taiwan Province and Hong Kong; the other three species,i.e.Mesophyllum mesomorphum (Fosl.)Adey,Lithoporella melobesioides Foslie and Neogoniolithon trichotoinum (Heydr.) Setchell et Mason are recorded :for the first time from the Chinese Waters. Recently， it has been reported[1] that Lithoporella melobesioides was a1so found among the Early Tertiary Calcareous Algae collected from the Qomolangma District，Himalayas.