The present paper deals with twenty four speeies of the genus Gracilaria Grev. collected from the China coast. Five of them, namely, G. articulata, G. firma, G. hainanensis, G. rubra and G. tenuistipitata are here described as new to science and described as follows. Six of them, namely, G. cacalia (J. Ag )Dawson, G. gigas Harv, G. megaspora ( Dawson )papenfuss, G minor(Sond ) Durairatnam, G salicornia (Ag )Dawson and G. sjoestedtii Kylin are found and now added to the list of the marine flora of China. The remaining thirteen species of Gracilaria, including one pecies with newly eombined name, viz., G, spinuiosa (Okam.) C.F. Chang et B. M.Xia, are credited to Chinese waters. namely, G. arcuata Zan. G. blodgettii Harv.,G.bursa-pastoris (Gmel.) Silva, G. chorda Holm, G. coronopifolia J.Ag.,G.crassa Harv., G. eucheumoides Harv, G. textorii (Sur )De-Toni,G. verrucosa (Huds. )Papenf, G. corticata J. Ag.,G. lingula J.Ag.and G. punctate (Okam.) Yamada. Among these, no specimens of the last three species are present in cur collection of Chinese marine algae. It is to be noted that the records of “G. corticata and G. lingula” are probably erroneous, but since the specimens on which these records were based are not available now, it is not possible to correct the identifications at this time. Antheridia of G. crassa and G. minor as well as tetrasporangia of G. megaspora are reported herein for the first time. The species name Gracilaria purpurascens Harv. ex J. Agardh (1884) of Gracilariaceae is a later homonym of G. purpurascens (Huds. )Greville, a name previously and transferred to Cystoclomium by Kützing (1843).Therefore, this later homonym must be rejected. Since Rhodymenia spinulosa Okamura (1934), which was relegated to a forma of Gracilaria purpurascens (Harv.)J. Ag. by Yamada(1941), is the older, it is necessary to elevate the name as Gracilaria spinulosa (Okam. ) C. F.Chang et B. M, Xia, comb. nov. Consequently, the name G. purpurascens (Harv.) J. Ag. f. purpurascens is untenable. G. spinulosa f srilankia C F Chang et B M, Xia nom.nov. All specimens, including the types of new species, are deposited in the Herbarium of the Institute of Oceanology, Academia Sinica. Of the critera which may be used in distinguishing species of Gracilaria, we have found the structure of the pericarp in the cystocarp as seen in longitudinal section to be the most satisfactory, and in this paper the decidable division of species has been based on this character.