Abstract: The present paper deals with the structure of the thalli and development of the reproductive systems of four species of Liagora, namely, L. pinnata Harv. and L. setchellii Yamada, both from Xisha Qundao, and L. boergesenii Yamada and fi. decs- sata Mont., both from Taiwan sheng. The development and position of their cystocarpid involucral filaments and the formation of the gametangial clusters were described. The names of sections were also discussed. It is suggested that the develop- ment and position of the involucral filaments may serve as taxonomic characteristics. The authors agree with Yamada and Chiang that the external feature and position of the gametangial clusters of L. pinnata are easily distinguished from those of the other. We consider the present names of the section (Farinosae, Validae, Mucosae) are inadequate.