¡§ Sea grape ¡¨ named by Japanese is Caulerpa lentillifera having erect branches with spherical ramelli. The length observed in field is 3 cm but may elongate over 10 cm after cultivation. While it is generally recognized by Taiwanese for all edible Caulerpa with spherical ramelli. Caulerpa microphysa collected from Taiwan northeast coast having 3 cm erect branch, but was recorded as 1 cm. To find the Caulerpa with longer erect branch field survey was conducted monthly in Taiwan south coast¡]Hsiao Liu Chiu and Kenting¡^ for one year from October 2006. Six species including C. racemosa var. macrophysa, C. microphysa, C. peltata, C. serrulata, C. sertularioides and C. racemosa var. turbinata were collected. The other two species C. lentillifera and C. racemosa var. occidentalis are acquired from the aquaculture ponds. In total 8 Caulerpa species are cultivated in aquariums with steady flow and nutrients. After cultivation, the morphology of C. racemosa var.macrophysa and C. peltata changed largely. All species with spherical ramelli only had 3-4 cm erect branches, but the C. microphysa strain from the northeast coast could elongat to 12 cm, having the same growth character as the Japanese sea grape. The morphology of the erect branches of C. microphysa changed with the temperature and the illuminance. Caulerpa microphysa could grow in 25-40 psu salinity, at 22-31.5 ¢J and 100-400 £gE/m2/s, the best growth rate¡]26.4 ¡Ó 0.6 ¢H/day¡^found in 35 psu salinity, at 31.5 ¢J and 100 £gE/m2/s. The growth of C. microphysa in deep seawater was better than in the surface seawater, that indicated there are some special nutrients in the deep seawater for the Caulerpa and need to study in the future.