Comparative studies were made on the yield, properties and composition of agar from 10 species (28 samples) of Gracilara collected on the China coast. The results obtained are listed in Tables 1 and the infrared spectra of which are shown in Figs.1,2,and 3. There exists. a close correlation between the physical properties ( gel strength, gelation and melting temperature) and the chemical composition. The gel strength, gelation and melting temperature of agar extraeted have the positive correlation with 3, 6-anhydro galactose content and the negative correlation with sulfate content. The yield, properties and composition of, agars obtained are different and dependent on the species of Gracilaria, the season and site. Of eollection. Comparatively speaking, G.verrucosa, G. tenuistipitata and G. sjoestedtii at raw materials for agar production are better than other species studied.